Can create account folders on WebDAV but note creation fails

I cannot create notes in an account on a WebDAV server. The account is created, a directory OpenTodoList is created with another directory inside with an .otl extension name. But that directory is always empty: making a first note, or trying to sync, both fail (log below) with no files created on the remote side.

The https WebDAV server works with other applications (Zotero, Joplin). It is hosted on Dreamhost.com.

This is OpenMedia List 3.22.0 in flatpak, running on Debian Buster 10.

Here is the log output:

[{"message":"\"Starting synchronization\" ","time":"2020-05-09T19:14:59.419Z","type":"Debug"},{"message":"\"Creating the remote top level directory\" ","time":"2020-05-09T19:14:59.420Z","type":"Debug"},{"message":"\"There was a network error: ContentNotFoundError\" ","time":"2020-05-09T19:14:59.706Z","type":"Error"},{"message":"\"There was a network error: ContentNotFoundError\" ","time":"2020-05-09T19:15:00.796Z","type":"Error"},{"message":"\"Unexpected HTTP code received when getting remote folder entry list: '301'\" ","time":"2020-05-09T19:15:02.015Z","type":"Warning"},{"message":"\"Failed to get entry list for ''\" ","time":"2020-05-09T19:15:02.015Z","type":"Warning"},{"message":"\"Synchronizing '/home/michael/.var/app/net.rpdev.OpenTodoList/data/RPdev/OpenTodoList/{df22b986-7d4a-4948-9b94-7bf72e70202b}'\" ","time":"2020-05-09T19:15:02.016Z","type":"Debug"},{"message":"\"Failed to synchronize top level directory!\" ","time":"2020-05-09T19:15:02.016Z","type":"Warning"},{"message":"\"Synchronization finished\" ","time":"2020-05-09T19:15:02.017Z","type":"Debug"},{"message":"\"Starting synchronization\" ","time":"2020-05-09T19:15:02.026Z","type":"Debug"},{"message":"\"The last sync completed with errors - doing a full sync\" ","time":"2020-05-09T19:15:02.027Z","type":"Warning"},{"message":"\"Unexpected HTTP code received when getting remote folder entry list: '301'\" ","time":"2020-05-09T19:15:02.274Z","type":"Warning"},{"message":"\"Failed to get entry list for ''\" ","time":"2020-05-09T19:15:02.274Z","type":"Warning"},{"message":"\"Synchronizing '/home/michael/.var/app/net.rpdev.OpenTodoList/data/RPdev/OpenTodoList/{df22b986-7d4a-4948-9b94-7bf72e70202b}'\" ","time":"2020-05-09T19:15:02.274Z","type":"Debug"},{"message":"\"Failed to synchronize top level directory!\" ","time":"2020-05-09T19:15:02.274Z","type":"Warning"},{"message":"\"Synchronization finished\" ","time":"2020-05-09T19:15:02.275Z","type":"Debug"},{"message":"\"Starting synchronization\" ","time":"2020-05-09T19:16:07.734Z","type":"Debug"},{"message":"\"The last sync completed with errors - doing a full sync\" ","time":"2020-05-09T19:16:07.735Z","type":"Warning"},{"message":"\"Unexpected HTTP code received when getting remote folder entry list: '301'\" ","time":"2020-05-09T19:16:07.942Z","type":"Warning"},{"message":"\"Failed to get entry list for ''\" ","time":"2020-05-09T19:16:07.942Z","type":"Warning"},{"message":"\"Synchronizing '/home/michael/.var/app/net.rpdev.OpenTodoList/data/RPdev/OpenTodoList/{df22b986-7d4a-4948-9b94-7bf72e70202b}'\" ","time":"2020-05-09T19:16:07.942Z","type":"Debug"},{"message":"\"Failed to synchronize top level directory!\" ","time":"2020-05-09T19:16:07.942Z","type":"Warning"},{"message":"\"There was a network error: ContentNotFoundError\" ","time":"2020-05-09T19:16:08.053Z","type":"Error"},{"message":"\"Unexpected HTTP code received when getting remote folder entry list: '404'\" ","time":"2020-05-09T19:16:08.053Z","type":"Warning"},{"message":"\"Failed to get entry list for '2020'\" ","time":"2020-05-09T19:16:08.053Z","type":"Warning"},{"message":"\"Synchronizing '/home/michael/.var/app/net.rpdev.OpenTodoList/data/RPdev/OpenTodoList/{df22b986-7d4a-4948-9b94-7bf72e70202b}/2020'\" ","time":"2020-05-09T19:16:08.053Z","type":"Debug"},{"message":"\"Failed to synchronize '/2020'\" ","time":"2020-05-09T19:16:08.053Z","type":"Warning"},{"message":"\"There was a network error: ContentNotFoundError\" ","time":"2020-05-09T19:16:08.103Z","type":"Error"},{"message":"\"Unexpected HTTP code received when getting remote folder entry list: '404'\" ","time":"2020-05-09T19:16:08.104Z","type":"Warning"},{"message":"\"Failed to get entry list for '2020/5'\" ","time":"2020-05-09T19:16:08.104Z","type":"Warning"},{"message":"\"Synchronizing '/home/michael/.var/app/net.rpdev.OpenTodoList/data/RPdev/OpenTodoList/{df22b986-7d4a-4948-9b94-7bf72e70202b}/2020/5'\" ","time":"2020-05-09T19:16:08.104Z","type":"Debug"},{"message":"\"Failed to synchronize '/2020/5'\" ","time":"2020-05-09T19:16:08.104Z","type":"Warning"},{"message":"\"Synchronization finished\" ","time":"2020-05-09T19:16:08.104Z","type":"Debug"},{"message":"\"Starting synchronization\" ","time":"2020-05-09T19:16:20.247Z","type":"Debug"},{"message":"\"The last sync completed with errors - doing a full sync\" ","time":"2020-05-09T19:16:20.247Z","type":"Warning"},{"message":"\"Unexpected HTTP code received when getting remote folder entry list: '301'\" ","time":"2020-05-09T19:16:20.437Z","type":"Warning"},{"message":"\"Failed to get entry list for ''\" ","time":"2020-05-09T19:16:20.437Z","type":"Warning"},{"message":"\"Synchronizing '/home/michael/.var/app/net.rpdev.OpenTodoList/data/RPdev/OpenTodoList/{df22b986-7d4a-4948-9b94-7bf72e70202b}'\" ","time":"2020-05-09T19:16:20.437Z","type":"Debug"},{"message":"\"Failed to synchronize top level directory!\" ","time":"2020-05-09T19:16:20.437Z","type":"Warning"},{"message":"\"There was a network error: ContentNotFoundError\" ","time":"2020-05-09T19:16:20.530Z","type":"Error"},{"message":"\"Unexpected HTTP code received when getting remote folder entry list: '404'\" ","time":"2020-05-09T19:16:20.530Z","type":"Warning"},{"message":"\"Failed to get entry list for '2020'\" ","time":"2020-05-09T19:16:20.530Z","type":"Warning"},{"message":"\"Synchronizing '/home/michael/.var/app/net.rpdev.OpenTodoList/data/RPdev/OpenTodoList/{df22b986-7d4a-4948-9b94-7bf72e70202b}/2020'\" ","time":"2020-05-09T19:16:20.530Z","type":"Debug"},{"message":"\"Failed to synchronize '/2020'\" ","time":"2020-05-09T19:16:20.530Z","type":"Warning"},{"message":"\"There was a network error: ContentNotFoundError\" ","time":"2020-05-09T19:16:20.596Z","type":"Error"},{"message":"\"Unexpected HTTP code received when getting remote folder entry list: '404'\" ","time":"2020-05-09T19:16:20.596Z","type":"Warning"},{"message":"\"Failed to get entry list for '2020/5'\" ","time":"2020-05-09T19:16:20.596Z","type":"Warning"},{"message":"\"Synchronizing '/home/michael/.var/app/net.rpdev.OpenTodoList/data/RPdev/OpenTodoList/{df22b986-7d4a-4948-9b94-7bf72e70202b}/2020/5'\" ","time":"2020-05-09T19:16:20.596Z","type":"Debug"},{"message":"\"Failed to synchronize '/2020/5'\" ","time":"2020-05-09T19:16:20.596Z","type":"Warning"},{"message":"\"Synchronization finished\" ","time":"2020-05-09T19:16:20.597Z","type":"Debug"},{"message":"\"Starting synchronization\" ","time":"2020-05-09T19:16:35.492Z","type":"Debug"},{"message":"\"The last sync completed with errors - doing a full sync\" ","time":"2020-05-09T19:16:35.493Z","type":"Warning"},{"message":"\"Unexpected HTTP code received when getting remote folder entry list: '301'\" ","time":"2020-05-09T19:16:35.789Z","type":"Warning"},{"message":"\"Failed to get entry list for ''\" ","time":"2020-05-09T19:16:35.789Z","type":"Warning"},{"message":"\"Synchronizing '/home/michael/.var/app/net.rpdev.OpenTodoList/data/RPdev/OpenTodoList/{df22b986-7d4a-4948-9b94-7bf72e70202b}'\" ","time":"2020-05-09T19:16:35.789Z","type":"Debug"},{"message":"\"Failed to synchronize top level directory!\" ","time":"2020-05-09T19:16:35.789Z","type":"Warning"},{"message":"\"There was a network error: ContentNotFoundError\" ","time":"2020-05-09T19:16:35.843Z","type":"Error"},{"message":"\"Unexpected HTTP code received when getting remote folder entry list: '404'\" ","time":"2020-05-09T19:16:35.843Z","type":"Warning"},{"message":"\"Failed to get entry list for '2020'\" ","time":"2020-05-09T19:16:35.843Z","type":"Warning"},{"message":"\"Synchronizing '/home/michael/.var/app/net.rpdev.OpenTodoList/data/RPdev/OpenTodoList/{df22b986-7d4a-4948-9b94-7bf72e70202b}/2020'\" ","time":"2020-05-09T19:16:35.844Z","type":"Debug"},{"message":"\"Failed to synchronize '/2020'\" ","time":"2020-05-09T19:16:35.844Z","type":"Warning"},{"message":"\"There was a network error: ContentNotFoundError\" ","time":"2020-05-09T19:16:35.896Z","type":"Error"},{"message":"\"Unexpected HTTP code received when getting remote folder entry list: '404'\" ","time":"2020-05-09T19:16:35.896Z","type":"Warning"},{"message":"\"Failed to get entry list for '2020/5'\" ","time":"2020-05-09T19:16:35.897Z","type":"Warning"},{"message":"\"Synchronizing '/home/michael/.var/app/net.rpdev.OpenTodoList/data/RPdev/OpenTodoList/{df22b986-7d4a-4948-9b94-7bf72e70202b}/2020/5'\" ","time":"2020-05-09T19:16:35.897Z","type":"Debug"},{"message":"\"Failed to synchronize '/2020/5'\" ","time":"2020-05-09T19:16:35.897Z","type":"Warning"},{"message":"\"Synchronization finished\" ","time":"2020-05-09T19:16:35.898Z","type":"Debug"}]