mac shutting down when using Adobe and mirroring my screen to a projector

A system crash usually means a low level failure such as a driver (bad video card driver, etc), failing hardware (hard disk, video card, etc.) or damaged OS installation.

If you run with just Photoshop with GPU disabled, does the mac still crash?

You can check "Use Software Rendering" and restart to disable it in Bridge.

Try logging into another account (you may need to make one), still crashing? 
Try starting up in Safe mode (hold down Shift Key when booting), still crashing? 
You might want to try running a free utility like Onyx: still crashing? 
https://www.titanium-software.fr/en/onyx.html
Also view:
https://www.macworld.com/article/352902/onyx-review-macos.html
https://www.macworld.com/article/224955/how-to-reset-a-macs-nvram-pram-and-smc.html
From Adobe:
https://helpx.adobe.com/photoshop/kb/basic-troubleshooting.html

My desktop randomly shuts down when using Photoshop or Bridge 22 and I am connected to a projector thru HDMI to mirror my screen. Sometimes I can go days without issues but then it will shut down 3 times in a row while using software. Have no issues if PS & Bridge are not running. Seen other people having similar issues but never seeing a solution and they are using a second display monitor not a projector mirroring. Has anyone found a solution??? I have turned off my graphics card when using PS but don't see that option for Bridge.

iMac (Retina 5K, 27-inch, 2020)

3.8 GHz 8-Core Intel Core i7

32 GB 2667 MHz DDR4

AMD Radeon Pro 5500 XT 8 GB