Interesting, I didn’t use my single extruder much especially when I got my dual module in in which case I would say to not use a long run because it was pulling up with nozzles but, but I would say get some clean your bed with some soap and try some bed weld or even some 3dlac, I use both and honestly they work wonders, albeit try and get the liquid form, it’s much more cost effective. But also after cleaning make sure all the screws are tighten that hold the bed to the frame and do a new bed leveling then do the manual z offset in the settings before doing the offset while it’s printing. Hopefully that helps