Posteo and Odyssey 1.23 (r5 b7)

I noticed that logging with Odyssey to 'Posteo' (posteo.de) stopped to work a couple of days ago... The login button is now inactive and has the text: "Please enable javascript". Javascript is 'on' in my settings, though, and I have not changed lately any settings of Odyssey. 'Spoofing' has not any effect on this issue.

Posteo's customer support said that they do not 'lock' intentionally any software (like some other companies!), and suggested to delete cookies and caches. But I checked that I have not any cookies saved for Posteo.

So, what might be wrong? Does it still work for any other user?