Brush Tool Glitch on New Mac Mini M4 Pro – Gradient Works Fine, Any Fixes?

@Adorable_art0516 Just checking to see if you were able to resolve your issue with any of the troubleshooting steps shared. 
^CM

Adorable --

• did you migrate to the Mini from whatever you had before (what did you have before)? [my fever may be causing me to misremember my moves]
• or did you install from Creative Cloud?

(teach me how to use Whatsapp to capture screenshots!)

@D Fosse  will be along shortly to tell you about monitor profiles. 

Whoops!  Maybe not for a bit as it's 12:30am where he lives.

@Adorable_art0516 have you tried resetting Photoshop preferences? Resetting Photoshop preferences effectively returns Photoshop to its default, "factory" settings, as if you just installed it for the first time. This can be a very useful troubleshooting step when Photoshop starts behaving unexpectedly, experiencing crashes, or if certain tools and panels aren't working as they should—BUT...Before resetting preferences, if you have highly customized settings (especially custom workspaces, keyboard shortcuts, or actions), it's a good idea to save them first. Photoshop allows you to save these elements so you can reload them after the reset. This way, you don't lose all your personalized configurations.