I know this is an older thread but the issue seems to persist into QB2023 as well.

I too have a 3 monitor set-up and couldn't figure out the missing zoom selector issue until you mentioned the screen coordinates.  I have a laptop which is centered between and below my two extended monitors.  The laptop was set as my primary display and QB worked just fine there, but that is not my "working" monitor so I moved QB to the upper left monitor.  That's when the issue became apparent.  I tried moving QB to the upper right monitor with the same result.

I was able to correct the issue by going into my Display Settings and selecting my upper left monitor as my primary display.  A few things happened :

1.  The zoom selector issue was resolved and I was able to click into the transaction details once again on both upper monitors.

2.  The text on-screen within QB was clearer (not sure why this was an issue in the first place).

3.  My desktop shortcuts moved to the new primary monitor, which wasn't a big deal for me, I only had a few.

So, not sure how this will work out for everyone, but that worked for me.

Good luck!