I’ve just upgraded to a new iMac Studio with latest OS Monterey 12.6 , I’ve had trouble when I want to Select several entities/components by clicking with the cursor then I hit Shift and then select several entities. The Plus sign appears and quickly disappears. It happens inconsistently/entermentantly. I’ve rebooted to get it to work again but this time it won’t correct.
I’ve got a couple of other items that might be the cause so I’m trying to isolate the problem. I’ve got a new mouse, new keyboard (not apple) and dual monitors with a questionable work around to use my old iMac as a monitor so anything can be a cause. Help!