I had the same issue (still have) but my workaround is opening the plugin via the new resources menu (Shift+I). Afterwards, they do appear within the quick actions popup.
As for your second point, plugins can now be run without having to install them beforehand, so the ones listed have been installed.
re point 2 - all of those plugins are installed, hence the confusion - they should all be labelled “Installed plugins”. But tbh - given the width of the quick action view, it’s wasted space, I’d rather they were all without that additional text.
+1 on this issue.
I noticed this occurring after the major feature updates following ConFig 2023.
Using the resources menu (Shift + I) shared by @Toni didn’t help me, unfortunately.
For me, at least, it seems the issue is coming from the fact all of my plugins are coming from my organization. I can still run plugins using the menu command
(Figma > Approved plugins for [org name] > From [org name])
but I’m not able to run any of those same plugins using the Quick Command search (cmd/ctrl + /)