photoshop making unwanted duplications

HI All.

I have photoshop cc 2020. When i move anything the object will stay in the previous position almost like a duplication. I have to flatten it and it will dissapear. its fraustrating as i have to now flatten and undo everytime i do something. if there is existing text i hilight it and write the new wording which i can see however the old wording remains until i flattern it and undo then only will it disappear. please help