Am on very latest Comodo as well.
All my taskbar icons (as per first post) were invisible.
When i hovered i could sorta see ever so faintly a box outline, but nothing else.
Right click and each respective label-text appeared so i knew icons were there, just no graphics (or invisible)
That said, on the far right side of screen/taskbar where active programs are normally by default, they were visible, including comodo.
When you wrote ‘invisible’ it felt similar enough to mention.
Sounds like your issue is different enough, especially now that you tried, so will leave you to it.
Hope you get figured out!