Clear the chamber, seat the flexible plate and remove plastic from the nozzle before leveling. Residue changes the pressure measurement and can create a false mesh.
Run automatic leveling from the K1C interface and let it finish without touching the enclosure. Print a broad single-layer pattern using a known PLA profile.
If the entire layer is too high or low, repeat the clean measurement and check the active profile. If only one area fails, inspect the plate, magnetic surface and bed mounting. Do not hide a severe local slope with arbitrary offsets.
Codes in the 2520 range can concern the K1-series pressure-sensing system. Record the exact code and use Creality’s matching article. Repeated sensor or wiring errors are service issues, not manual-leveling invitations.
The general bed leveling guide explains why chasing a Z-offset number rarely fixes a local slope, which applies just as much to the K1C’s automatic mesh. Leveling is usually one of the last checks after the enclosure setup and self-check routine and before trusting results from the first print walkthrough.