Mate do not ever be surprised if it is hardware related. I am a newbie but learning super fast that don’t assume the machine works, in other words have a ■■■■ load of spares ready. Support is a 3 day between question and answer so if you do not learn to fix it yourself you may as well chuck it in!!! Sorry but that is my impression. Most things are pretty easy when you get into fixing it. I would say 99.9% of K2 Pro owners & K2 owners have no idea that the belts are “manually” adjusted. I have a K2 Plus which has auto adjusting belts arriving today so I can 100% guarantee that mine on my 2 x K2 Pro’s are exact. Also the previous firmware ending in 66 fixes 90% of issues, the latest one ending in 94 is a bug ridden paradise of errors. Takes about 2 minutes to rollback. USB stick, go to Creality Downloads, pick out the firmware ending in 66 then put it on the USB, stick it in the machine and “update”. Turn off automatic updates. Hope this helps.
Did you recheck the connector for the motor? I have had a connector get loose before and sometimes you just need to reseat it.
Which K series printer is this?