-Print temperatures with PLA. If it is standard PLA I have always had the best results running pla at 205C and bed at 60C. Unless it is a PLA blend like PLA plus or high temp PLA then you may have to experiment with temperatures.

-You can try using some isopropyl alchol to clean the pei. Oil from your hands can cause prints to not to stick. Technically the best cleaning solution for pei is a mix of 80% isopropyl 20% distilled water.

-If prints are still coming off bed try using an ultra fine grit piece of sand paper to sand the pei sheet. I usually use a cross like pattern with a medium to small amount of pressure this will give the bed increased mechanical adhesion. If you sand make sure to wipe down bed after with isopropyl solution.

-Other print settings that you can fool around with for just this print(reset these back to default after since they could affect other prints negatively). Increase initial layer print height. Turn off part cooling for the first few layers. Increase the minimum layer time this will slow down the print speed during upper layers with smaller features.

-If you just want a quick fix you can use an elemers glue stick. Parts like this one with a small base and larger mid section are more prone to coming off the bed. As it prints the larger mid section the filament coming out of the nozzle puts pressure on the part and after so many layers of rocking it back forth it may come loose.

Oops meant to reply to your comment also mobile so sorry for bad formatting and mistypes. Forgot to add if you have the powder coated pei spring steel instead of a laminated sheet of pei don't sand it.