Internal Server Error on login to any Mozilla service

I’ve created a new account here to report a login problem with my primary account @peci1. I don’t remember anymore which login method I used when creating the account. But it’s highly probable that I used Firefox login.

Nevertheless, I can no longer login to some Mozilla services. I tried chat.mozilla.org, discourse.mozilla.org at least. I can, however, login into the desktop Firefox browser, and I also succeeded logging in to AMO using the same account.

The attempt to login to chat.mozilla.org ends with Internal Server Error and URL https://sso.mozilla.com/forbidden?error=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJjbGllbnQiOiJkaXNjb3Vyc2UubW96aWxsYS5vcmciLCJjb2RlIjoicHJpbWFyeW5vdHZlcmlmaWVkIiwiY29ubmVjdGlvbiI6ImZpcmVmb3hhY2NvdW50cyIsImV4cCI6MTYzODA2NzU2OSwiaWF0IjoxNjM4MDYzOTM5LCJwcmVmZXJyZWRfY29ubmVjdGlvbl9uYW1lIjoiIiwicmVkaXJlY3RfdXJpIjoiaHR0cHM6Ly9kaXNjb3Vyc2UubW96aWxsYS5vcmcvYXV0aC9hdXRoMC9jYWxsYmFjayJ9.LEF3GPWCTM4nk3v5UJffTQumenzk0iy7J3H-0qPuvWjwMzKJuRZIb608CmzpzEy3uSOCsC0LMZvSEDjswWgqs-LfgyA6L5wj7WekdkOTt5nvvoevXJ5-b8dyxRods1kCpoaYQ33VGulJ2S-AdxZw-ja6rqRr6sFH2cUdtSzTPpR5wDjyGnQO5YrW3R6vm9gCGksuv7Tu6UxH-J4q3yYUsC4_ujE-PHaXYILk-dwyeXFoYtOVeQv46AQLgUB35HkEkqrFKYYbNKvnFHco8gQQR7OeHIPNFigD9pj1Pzr7EZORiKMhaLnTRXKqkgpH2uPZ2POVCKLZb1azLErGkoQvbM4p2QPo1R6Iokpgz91xcRW37qfshvHmXVFwwcweiJKiPST0HP7M_lol7z9QLusxT30WM8juQEGcDmRVAxOYGk9Sv1KOgrfcR9-J44X0Ul1tHrD8tKep62Hfj6HaCa9ONBCV8RtyT1vNXqdT8g0tVSrR16iqGoy-WuhSfkJwXFiw8bm2sl3b6Eel-6jRbT_CU2Q1fXfu_wCwh4AGO_poaIQaQAB6Wa5boF7IVYq_BoSrTPgrGzbi2O5Qf5oQumrC8cRRfQUumwVx6OCFcP2zRBuNkzZPTNYDNJzgWWTuLDKtFr7LCLwIHxe_CEgzV1D--NBRDh3fOg7HuCQBdPTp2d4&state=g6Fo2SBRVU1nblFSeDdrRFJBeGdZUVRVRE1RNlJPWGZCWUFTY6N0aWTZIEVjbTZuSVYtVU1VYmNvR2VwdmZtTTBLRFM1T0NHVTl5o2NpZNkgcmVoZ2c5Y3FWbUhKYkh3M2pQWVV6b1U1QllZQkg2WEw

I tried to login from Firefox and Chrome, the result is the same. I also turned off all privacy addons (except the builtin privacy protection) while debugging this issue. I also tried to login via Github, and it failed in the same way (my guess is that Github tells IAM the same email address that has this problem, and IAM continues the same faulty path).

Thanks for any clues how to get my account working.