The keyboard shortcut to invert colors is Control+Option+Command+8. Because this uses the VO keys Control and Option, the only way to invoke it is by preceding it with the VoiceOver passthru command, VO+Tab. I have used this technique since first learning VoiceOver on a Mac some 8 years ago. First press VO+Tab, then invert colors with Control+Option+Command+8.
However, this sequence of keypresses no longer inverts colors. If VoiceOver is enabled, Control+Option+Command+8 doesn't work, regardless of whether it's preceded with VO+Tab.
I can disable VoiceOver with VO+F5, then invert colors with Control+Option+Command+8, then re-enable VoiceOver with VO+F5. That's the only way I've found to invert colors with a keyboard shortcut - disable VoiceOver first. But I've never had to do this before. I've always been able to use the VO+Tab passthru.
I'm seeing this with Mac OS 12.2.1. I can't tell you which version introduced the problem because I upgraded directly from v12.0, and it worked fine in that version.
Can anyone else confirm this bug?