Bed Level Calibration - Weird corners
I'm getting my Mk3s calibrated again after not using it over the summer, and I'm a bit confused. I used the standard bed level testing pattern, but I have no idea what's going on at both front corners. At first glance I'd say it's far too high, but the rest of the corner square is slightly too low. Not sure how that's possible, or how to correct it.
The separation from the print bed above the spaghettis is because I poked at it after printing, it didn't come out like that. Front right corner is similar, but not quite as bad. Rear corners are normal, aside from being textbook examples of being extremely low.
Filament is Polymaker Polylite PLA, extrusion multiplier and temperature already checked and seem good.
(I also have some issues with Linear Advance, but not as bad. I did the calibration pattern and my values seem to be correct, yet I keep getting the usual dog bone corners. Especially on overhanging slopes. The extra material also makes the corners bend upwards sometimes, which can cause issues.)