After 10.5.20 Upgrade: no vst plugins loading in projects


after upgrading from .5.12 to 5.20 all my projects dont load any VST anymore.
Anyone else experiencing this bug?

Plugin Manager tells me all VSTs are there and not blacklisted.

I can also make a new track and add one VST again. Works fine.
But not the “already there”-tracks from the project.

EDIT: after two more restarts, suddenly the plugins load again. very strange behaviour…
will look into it.