Fixing Firmware Headache

Hi all.I've been using my Creality ender 3 for about a year, and I really enjoy it.It worked well with stock settings out of the box for a while, but then I started having problems with bed levelling.The main problem I'm having is that it appears that the printer starts at a different 0 point for the z axis on every print.This means that no matter how carefully I level the bed, when I actually start the print it will reset itself to a different and incorrect 0 point.I thought I had identified the problem as a broken z stop, and figured I could fix the problem by installing a CL Touch.I purchased and installed the CL Touch using the instructions from this video.https://www.youtube.com/watch?v=9W_0jv3dgoI&t=176sI used the standard firmware from the Creality website, and removed the z stop.Unfortunately this has not fixed my problem. I manually level the bed with the printer set to the Z 0 point.When starting the printer it automatically levels the bed using the sensor, and then starts printing at a different height than the height the bed was levelled to.I'm starting to believe this is being caused by a firmware problem, which is beyond my experience level to fix.Some people with similar problems seem to have made firmware changes that have fixed this problem, but require running a whole different firmware.If anyone can help me with this problem I would really appreciate it, as my printer is sitting idle until I can remedy this issue.Thanks and have a great day!