Trello integration not working

Dear team

I've added a Trello board yesterday as I created the repository (a team repo) and this morning I tried to add an additional board. This operation failed with the message "Something went wrong
Try refreshing the page" (see also attachment).
From then on this is the result of any attempt to connect.

I saw other issues where the solution was to start from Trello and tried also that path, but I'm unable to select any repo.

I've tested also with another repo, but got the same error.

Is there anything I can do to link the boards?

Thanks

Regards

Claudio