12.1.2 VERY Unstable. No redraw, crash, using Undocked Panel

The exact same issue has now happened to me on two different completely independent systems.  Both running 12.1.2

Problem -  When moving an un docked window, the source and record windows stop updating and freeze, occasionally with a white screen, but can also be in the middle of a re-draw, or can go black.  When this happens, you can not scroll through the time line, or the source, but you can hit play and hear audio.  You must crash Premiere.  It will either freeze and not exit - or if it does exit, it remains running in the background and must be terminated.  Then you frequently can not export.  Media Encoder freezes and must be terminated.

Two different systems, two different CC accounts do EXACTLY THE SAME THING.  The only common issue I can find is that in both cases, the project was "up-converted" from a previous version.  Sometimes the issue will clear on a restart of Premiere, sometimes on a restart of Windows, and sometimes you need to manually trash the preferences.

I have been on the phone with Adobe for a grand total of 12 hours with 3 different techs, and no one can seem to fix this issue. The last thing I got was "Well, Premiere is really only designed to run on a single monitor" which is complete BS - AND - the problem still happens when run on a single monitor.  We have tried cashe clears, different media, new user accounts, uninstall and reinstall of graphics drivers, updated graphics drivers, clean reinstall of the program using CC Cleaner, and multiple other steps with no improvement.  The tech can get it working long enough to  get me to say the words "appears to be resolved" so they can get off the phone call but in less than half an hour I'm right back where I started and back on the phone.   I CANNOT USE THE SOFTWARE THIS WAY.

System 1 is literally BRAND SPANKING NEW, right out of the box.  It has no other software on it.   System 2 has run Premiere in a multiple monitor situation for nearly 5 years without a major issue until this update.

System 1 - Alienware I9, 32gig ram, Nvidia 1080 video card.  Windows 10 pro, 64 bit

System 2 - HP Envy, i7, 12gig ram,  Nvidia 840m, Widows Pro, 64 Bit

Can anyone make any suggestions????  At this point I cannot revert because the projects already have work done to them which would be lost.  I have not verified the problem with a new, clean project.  If anyone from Adobe is listening, this is a HUGE problem that needs to be solved.