iphone xs max crashing

My iPhone XS Max started crashing since Friday night. I first noticed it was on the black screen with the apple logo. It was unresponsive, I tried to do reset several times until finally it worked, but unfortunately it was not working properly. It will lag the apps will not open. So I reset to factory settings. Didn't work, same thing crashes randomly. Apps won't work, they crash once you try and open them. Does anyone have a solution?