Okay I’ve tried out some older versions but couldn’t get it to work. Just started using my setup at the end of November but can’t remember if it worked back then.
Maybe you can try to find out which update caused the issue.
I have found another post regarding the same issue :Server refuses to transcode Live TV (720p)
I think there is no direct way to get in contact with the devs. Maybe a moderator can pass on this bug to the developers ?