Trackpad selection issue with High Sierra
When selecting objects or drawing with any of the tools, Illustrator is not recognizing the trackpad release, so objects remain selected and the only way to deselect them is to Command-tab out of the application. I was able to duplicate this problem on my laptop as well. Appears to be related to the trackpad because the same issue doesn't appear to happen when I use a standard mouse.
Mark Gould commented
I'm currently experiencing anomalies with my trackpad in Illustrator CC2022 on iMac with OS Monterey. At times pinch/zoom produces no result and then goes away. I've also experienced the issue of the cursor not deselecting objects when you move the cursor. Both are very intermittent, and then it goes away, repeat.
...And this is with Illustrator CC 2018 ( posted the comment about wireless trackball)
It happens to me with a wireless trackball (Kensington Turbo Mouse) as well as the trackpad.