I meant "higher" as in moving the bed higher, ie closer to the head, ie more squished. Lower is inverse.
I've never had a problem with parts not sticking. I'm using PLA. I have the opposite problem. I'm using a sharp chisel to try and get under the parts and get them off with breaking them.
I think I originally had the bed too close/squished. Apparently material couldn't come out of the head sufficiently. Looks like the bed may not be perfectly flat, or at least the mat onto of it. I've read people suggest having a glass bed.