Desktop client can't connect after password has been changed

I am using NextCloud 13.0.1 and several devices synchronize data with it. Everything worked fine until I used the web interface and changed my user password. Now the Linux desktop client can’t connect any more, although it asks me for the new password from time to time. Every other devices, no matter if Android or pc, can access the server as before after I typed in the new password.

Even more strange: if I create a new account in the desktop client, same user, same new password, it connects to the server again. But I simply don’t want to recreate each and every folder pair, therefore I’d like to use the old configuration.

What is wrong there? Why does the desktop client have this problem, while no other connecting client does not have it?

I’m not sure if the ownCloud forums is the best place to ask for support for a different product. Maybe that software has an own support forums?

Actually, is the address that the desktop client announces to look for help. But I just noticed my mistake. Sorry!

Question: how can I delete a thread that I started at the wrong place?