Ender-3 V3 SE printhead hitting object being printed

@rc-arty
I’ve had this same issue off and on. Some things that I have found,
1 Tighten ALL mounting screws (don’t for get the print bed screws too)
2 Tighten printer head belt a bit
3 Disable ironing and combing in your slicer settings
4 Enable Z hop and retraction
5 Set print bed temp to 60°c and let it sit at that temp for about 5 minutes,
Notate the measurements on the grid, and repeat and compare.
If the measurements are not fairly consistent, check all the screws again.
6 Re-run auto-leveling and auto z axis offset
7 If you have the nebula kit installed, DO NOT run the print bed sensor calibration
only run the printer head calibration.
I’m assuming your printer firmware and control pad is fully up-to-date.
Just to note: I recently installed Creality print 5.X (Windows), and this issue came back. Wasn’t sure why, and really didn’t want to deal with it at that moment, so I just went back to using 4.3.7.1
In Creality print app, there are several calibration section. I would recommend running those calibrations, reference the tutorials, and make any necessary adjustments.