Apple was a bit sneaky around this stuff — they automatically run Intel AU plugins under Rosetta (so that Logic can work) but they didn’t do it for VST plugins.
There is a known problem with some AU plugins where no sound comes out if you’re using 44.1k sample rate and we believe this is fixed for the next release. If you happen to be running at 44.1k, can you try another sample rate?
On the other hand, when one mixes/matches Apple Silicon and Intel, frankly all bets are off — we’re comfortable that GP Native will work fine with Native plugins and GP Intel will work fine with Intel plugins (and although unsupported this seems to work fine under Rosetta) but mix/match - shaky - I certainly wouldn’t want to do a show with that setup