MP4 DV P5 videos have stopped working since the last release?

[TurkeyMan 18]

I eagerly installed the recent update hoping it would fix the playback issues that have been discussed at length, but I noticed no improvement to any of those issues.

What I have noticed since that update though, is that now much of my P5 content has also stopped working!

Normally, DV P5 in MP4 with EAC3+Atmos Audio was the gold standard for compatible modern streaming distributions, my old CX required P5 content to be MP4, and most P5 distributions are encoded in P4 for compatibility. My 'new' (over a year old now) G5 relaxed that requirement, and it can now play P5 in MKV or MP4.

But with this update, when I play a P5 file something weird happen; stats-for-nerds shows direct-play of both the video and the audio, but the container shows it's being transcoded for reasons I don't understand, and then the colours are all wrong because DV doesn't get decoded.

Any reason why the container transcoding suddenly started kicking in on unremarkable material that used to be working just fine? Has anyone else noticed this?

The surprise is that P5 is still working if it's MKV, but all my MP4 P5 content (the vast majority of P5 content) is transcoding the container now and it's all unwatchable.

There's no workaround for this; nothing can be done to make P5 content play correctly if an incompatible stream is fed to the TV

I can't find any way to downgrade to the prev version... does anyone know any resolution, or are we SOL for another few months?