ProTools and Mojave to Monterey . . .

[JoeM]

You might have luck if you break the record process down into multiple steps. Try bouncing down all you background tracks with the VIs so you’re left with a stereo or even a mono track. Create a new session, import your bounced audio and record your vocal (s) to this session. After the vocals are recorded you have a choice of finishing in the new session if your bounce mix was what you want on the final or import the vocal track back into your original session to finish there.