Hi @popcornscavenge ,
Your phone may be suffering from [https://www.androidpit.com/how-to-fix-the-ghost-touch-problem-on-any-android-device|ghost touching].
This could be related to the two small cracks in the screen which initially may not have been a problem but it may have gotten progressively worse.
Try starting the phone in [https://thedroidguy.com/2019/03/samsung-galaxy-note-9-safe-mode-wipe-cache-partition-and-reset-applications-1088680|safe mode] to eliminate the remote possibility that it is a downloaded app that is the cause of the problem.
If it doesn’t occur when using the phone in safe mode, then a downloaded app is the cause of the problem. The trick is to find out which one.
The more likely problem is that it is a faulty touchscreen (digitizer). It cannot be repaired, it has to be replaced.