Terraform remote state: No stored state was found for the given workspace in the given backend.

I'm building a new Gitlab.com Terraform repository and I would like to use the Gitlab Terraform states feature but it looks like it doesn't work at the time I'm opening this issue.
(I have managed to use it in the past for another project)

I'm able to initialise the state and I can see it in Gitlab.com, but then terraform plan fails with:

╷
│ Error: Unable to find remote state
│
│   with data.terraform_remote_state.default,
│   on remote_state.tf line 1, in data "terraform_remote_state" "default":
│    1: data "terraform_remote_state" "default" {
│
│ No stored state was found for the given workspace in the given backend.
╵

I have open a topic on the forum and created a public minimal repository reproducing the issue.