swap when one of the devices is acting as WIFI access point

On my Moto G this used to work till recently when the "recipient" was acting as the AP. After some updates it does not work at all and it appears f-droid is completely unable to connect the repo, without giving too many diagnostic details unfortunately.

It does not matter if the WIFI-ap device has any kind of internet connection.

If the "repo" is on the device acting as AP it never worked as f-droid is unable to create a valid URL - displays https://null:8888 in this case

Glad for any hints and known workarounds.