I did a visual inspection and I don’t see any build up. I generally clean the exterior of the phone regularly, because my skin is sensitive to sweat. So I keep things I touch regularly clean. (Phon, computer mice, keyboard, etc). I could just stick a toothpick in there and gently move around just to see if it knocks anything clear? I don’t want to damage anything by trying to fix it though, lol.
So, just asked Google Customer service about it. The answer does not make sense to me, but they said “Adaptive Charging on a Google Pixel phone may show the charging symbol even when it’s not plugged in because it charges to one hour before you unplug it.” They also told me several times that “You shouldn’t worry about it”.
This is not very satisfying, and doesn’t make sense, but it wasn’t going anywhere. I’m going to try turning off adaptive charging, because maybe it’s just really confused what my schedule is?