Recently we started having issues with our Build Server Integration for TeamCity. We are running YouTrack 2018.3, Build 46358, but it was not related to any update of YouTrack.
Previously we would commit something like "#PROJECT-123 Ready for testing Charlie" and it would show up in PROJECT-123, it would be marked as Status "Ready for testing" and assigned to "Charlie". This is no longer the case.
It does show up in PROJECT-123 issue, with the following commands and comment, but the comments seem to not be processed at all. Visually I can see that the little "i" (information) icon is not there at all. Previously it would either state "Command was successfully applied." or upon failure "Could not apply specified command." with a red warning triangle and the command in question marked.
What can have changed that caused commands to no longer be processed at all? To our knowledge very little has changed, and not really anything that specifically targeted the Build Server Integration.