Posting this because it was a simple thing but I couldn't figure out what was happening after the Photoshop 2020 update. I was trying to draw a rectangle shape by dragging my mouse starting from the top left corner, but it would go wonky and it was hard to draw.
Atfer selecting the rectangle tool under shape selections I went to the "settings" looking icon on the top toolbar. Under Path Options I unticked the one that said "From Center." Gee. I wonder who made that a default behavior. Hope this helps someone.
I haven't had this issue. I know my students had issues because of the shift key change.
Depending on what version you are updating from, the behavior of the shift key changed. Are you holding the shift key to constrain it? Try drawing it while holding the shift key and try drawing without to see if you get better results.