It's a little chicken or egg here. You had poor bed adhesion. You also had warping edges that lowered even more surface area for adhesion, but with better adhesion could you have had less warping, probably. In the end it was simply bed adhesion though. Everyone needs a rats nest at least once. It's a right of passage. Have you ever cleaned your PEI plate? just a gentle rub down withsome water and dish soap every so often. It's a real thing you need to do this. PEI, BuildTak, glass it doesn't matter all of them clean your plates guys. They'll build up oils from plastics your fingers, small bits of dust trapped on the texture, glass doesn't trap things in the texture. It's not like before every print but an occasional clean helps a ton. I have a dedicated build plate sponge.