K2 Plus Lines/Z wobble or banding… please helppp

Hey so I bought the K2 Plus and honestly I love everything about it, but there is one big problem these lines, I tried everything that is said online from speeds to loosening, tightening , pretty much everything except disassembling the lead screws and checking for how straight they are but they look pretty straight, I don’t know what to do, please help.

Hi, First of all, check if you are printing with dry filament. It is very important.
If Yes, do calibration of your printer. Temperature , PA, and retract.
If YES, try to reduce the speed.
If that didn’t help, I would have already looked at the extruder, maybe there are some mechanical problems.