Astra UHD Demo playback issues on Raspberry Pi 4

Hi there! My first post here, I very much appreciate all the dedication and hard work that goes into this. I've been a long time user of OpenELEC / OSMC on RPi3. I recently upgraded to an RPi4 and chose the free-er option from you guys.

Part of the reason for the upgrade was to try out the 4K stream I have on my satellite. I live in Ireland and use the Freesat DVB-S service. This gives me all the UK channels plus a demo channel called UHD1 - Astra UHD Demo. Unfortunately it doesn't play very well.

• The picture looks great but immediately starts to lag behind the sound.
• There isn't a lot of stuttering etc, but there are some odd things like a black frame a couple of seconds after playback starts and it does seem to be running slow.
• When I press pause, the sound stops but the picture keeps going until it catches up.
• If I let it play, things eventually break down with buffering and interruptions to sound.

A bit about my setup:

• LibreELEC 9.2.6 running on a 2GB RPi4
• Wired network connection. Speed Tester addon reports 195Mbps.
• TVHeadend running on a separate server (HP Gen7 Microserver)
• Satellite stream coming from a Grundig GSS.Box Sat>IP tuner/server
• 42" Panasonic 1080p TV (about 8 years old)

Any ideas?

Thanks & Kind Regards,

Graham

Thanks Da Flex I think it helped a bit but it didn't fix it fully. The thread you linked was to another called "Choppy video NHL addon" where you suggested the same thing. Was there another with more suggestions? I tried a few different deinterlace settings (apart from Auto and None) with no luck.

It's only a UHD demo channel from Astra 28E, so it's not a show stopper. But it would be nice to sort this. Should I post some more diagnostic information? I was thinking to record a snippet of the stream and try to "identify" in ffmpeg. Maybe repackage it into a different container (e.g. mkv instead of the transport/program stream that comes out of tvheadend)?