Knocking and thin layer of print on E3Pro
On my Ender-3 Pro I'm getting a knocking noise and a very thin layer of printed filament, but this only occurs on some areas on the right half of the bed. On the left half of the bed, it prints just fine.
There doesn't seem to be layer shifting, just very thin layers for the first 4-6 layers, and then it seems to print fine and the knocking stops.
Any thoughts? I've seen comments about upgrading the mainboard to 4.2.7.
Since it prints normally on some areas of the bed, I wouldn't think it is a nozzle, extruder, drive, spring, or reel issue. Is this a leveling problem?
I had something similar happen - it got better when I meticulously made sure my print bed was both flat and level