VST2 gui is not repainted with JUCE 7

I’m in the process of upgrading some small VST2 plugins from JUCE 6 to JUCE 7, and I have run into an annoying problem.
First of all these plugins are made to be used with an archaic host called Software Audio Console (SAC). SAC is a live sound mixer (like Waves LV1) and is only VST2 compatible.
In SAC it’s possible to create “snapshots” of given settings and if I create a snapshot and later update the snapshot the gui of my JUCE 7 plugins are not repainted after that. That means that the plugins still reacts to slider moves, button pushes and so on (I can hear the changes) but the slides and buttons are not repainted, so I can’t see that they changed until I close the editor and open it again. After closing and reopening the editor, the gui is updated, but it’s still not repainted when I change something.
I can recreate the behaviour with the simple GainPlugin and other of the example plugins, so the problem is not (only) with my code.
I’m using Visual Studio 2019 on Windows 10.
When I build the plugins with JUCE 6 they work fine in SAC so something changed with JUCE 7 that is causing the error.

I know it’s a long shot, but if anyone have an idea for something I could try, that could help me fix the error, I would really appreciate it.
Otherwise I’ll just stick with JUCE 6 for my old SAC-VST2 plugins!

Regards Peter O

I’d guess that this might be the commit that has changed things: Windows: Consolidate graphics invalidation regions · juce-framework/JUCE@05a4242 · GitHub

It’s a bit fiddly, but if you could undo those changes, or otherwise spin up your own thread for invalidating regions that runs on a constant timer (rather than being linked to the hardware), then that would narrow things down a bit.

Thank you for the reply, t0m.
I think that what you are suggesting is a bit over my skill level.
But thanks anyway!