Possibly moisture in the filament.
Was the filament loaded and exposed to air during the two weeks of no use?
What is the humidity where the printer is located?
Have you tried printing with a different material? This would help you determine if it is printer or filament related.
Every now and then my x1c will go crazy and print weird. I run the calibration and it is fine. I know when because it sounds loud and clunky when it changes direction at the end of a line. Recalibrate and it is fine, it is as if it forgets the correct linear advance settings once every 3 months. You may have the same problem, did you rerun the calibration on the printer?
EDIT: Same issue with my calibrated PETG profile. Same weird pattern. But this time I printed this not in the middle of the bead, instead it was at the front. So Its no a problem of the printbed
What size is your nozzle? This looks like a partially clogged nozzle.
You could try a cold pull or other methods to clean etc… I’d suggest googling some videos etc… Or search this forum, tons of posts and solutions to a clogged or partially clogged nozzle.
Maybe another issue altogether, just based on my limited experience and knowledge, his could be the issue.
Make sure your sheet profile in the slicer is set correctly for the sheet you’re using. It looks like the nozzle is too close to the bed, or the first layer line width is too great.
