Yes, it would be awsome if you can fix this issue.I didn't know about the Mantis entry - thanks
If it's still a problem with RTSP, post some logs and I'll take a look.
I'd also try the 'noStopMod29' TsReader from - https://forum.team-mediaportal.com/793746-post149.html - with RTSP.
Now, there is a workaround (stop and restart the player on each tuning) for this bug in the 4TR client, but this made tuning extremely slow. So if this issue is solved, the workaround can be removed.