I am using an Ultimaker 2+, with a glass build plate (sticker side up) and a 0.4mm nozzle, and up until recently it was printing just fine. I did a 14 hour print and it came out perfect, no defects, very smooth, works great.
However, since completing that print, I have been having a plethora of issues, which I've tried to fix with many different solutions such as lowering/raising the nozzle temp/heated bed temp, different ways procedures for leveling the bed, and adjusting settings in Cura, but nothing has fixed the issues.
Most commonly what happens is the initial layer will not adhere to the build plate in certain spots, or it will adhere initially, but after a minute or two, it will warp upwards off of the plate. Sometimes, filament in thin area will come out of the nozzle, onto the plate, and as soon as the nozzle changes direction, it pulls the filament with it, curling it up off of the bed. I have tried printing with a brim, but even the brim itself is having these issues.
I am using a black 2.85mm PLA, I have tried many temps between 185 - 210 C, and bed temps of 50-70, but the same problems occur regardless of settings.
A couple prints made it past the initial layer with only small problems, but those small problems ended up causing complete loss of plate adhesion later in the print, resulting in a complete failure.
At this point, I am not sure what to do to solve this issue, any help would be greatly appreciated!