OK, I've done some further troubleshooting and installed Waves v11 plugs instead. Beachballs are gone EXCEPT when I have the VU meter plugin
displayed - then Pro Tools transport becomes sluggish again, but still without beachballs.
If the VU is substantiated but not displayed, no problems - not that that makes it usable!
Having other Waves plug-in windows open doesn't seem to cause any issues. I haven't tested every plug-in because I don't have time.
Can anyone replicate this? I know the Waves reinstall is a bit of a pain, the article on how to go backwards is here:
https://www.waves.com/support/how-to-install-waves-v11
Cheers,
Nathan
iMac 27" 5k 2017
40GB RAM
PT|Ultimate 2021.7