Delayed notifications are one of the most enduring issues with Google Pixel phones, and Google seems to be aware of the issue.
I’m glad you intuited that I meant “gesture” navigation - had an autocorrect problem. There’s a bug I’ve seen for years where, when swiping back to home, the screen is unresponsive to taps for like a half second. Maybe that’s related? Apparently it’s more noticeable with third party launchers like mine.
I’ll have issues after taking a screenshot and navigating back - I just get a non-responsive black screen sometimes except for the navigation buttons. Those are partially unresponsive, and I have to tap them chaotically to get rid of the black screen.
I think the whole Android system navigation has been broken since Google started rolling it into the Pixel Launcher.