Command-Tab, application switching on a Mac, takes you from one app to the next.
For the new version of PL3 (3.1.2.42), if you switch from PL3 to something else and then back, there is a delay of several seconds before it appears on the Mac. In fact, I get about two seconds of a spinning beach ball before PL3 reappears.
No other Mac app I know of does that. The delay is long enough to make one think it is not responding, or that you hit the wrong keystroke.
I really like PL3 but discovering and working with new quirks with every release, even minor releases, is really tiresome. At this point I’m falling back on a copy I managed to stash in TimeMachine, and will leave Build 42 behind.