Ghost/phantom notifications and other sketchy things
This sounds like a failure of the digitizer. All sorts of phantom scrolls and clicks can happen when the hardware thinks it's detecting fingers making tap and scroll motions at random or repetitively.

If you open the calculator app, sometimes you can map out what parts of the screen are failing, but depending on the severity it may come and go in relation to percent of charge and temperature.

Long term, this is likely to get worse and need a repair - especially if the phone has been dropped and suffered either internal damage (which can be 100% invisible - especially if you have a case protecting) or can be totally unrelated to any damage - just that the fine wires in the display have stopped working as designed.