I think stock android (pixel software) has a feature that is called notification interval (something like that) and it means that if an app has sent me a notification, it can't send me another one for another x time. It's extremely useful especially for messenger that blasts you with notifications when you use multiple devices
I bought my LG V30 July 30, 2018. Still using it. The battery is of course not awesome but I'm not really a hard user so I get by. I installed a custom ROM around 2020. I'm on Lineage os 21 now. It's perfectly fine. I guess I'll upgrade somewhere this year cause the back cover seems to be coming off. I'm in no hurry though.
That seems the most possible