I could be wrong, but the 6 should be like the mini I have. Z-home is the top of the printer. If you are scraping the bed, you need to adjust Z-offset and/or thoroughly clean the nozzle and washers. During the auto-level, the bed should not deflect at all on the second touch. Mine runs Z down fast to find the approximate location, then goes up and down again slowly to get the final reading. The first one can deflect the bed a little, but the second one should not. If it does, you have a problem.
For cleaning, I heat the nozzle and use a blue scotchbrite pad. The washers usually clean up fine with a bit of alcohol on a paper towel. I hear PLA leaves a residue that can make the leveling a bit easier to throw off.
I use the slicer program to adjust Z-offset, so I can use different settings for each material. ABS needs to squish down pretty well for good adhesion, PLA not so much. The difference is small, 0.1mm or so, but it helps with print adhesion and removal later to dial it in for each material. Positive Z-Offset moves away from the bed. Try something stupid high like 1mm to make sure it works, then dial in slowly.
Once you get to where you aren’t hitting the bed, calibrate the E-steps for the extruder, make sure filament is measured properly. Then finalize the z-offset. If you’re doing it right, you should get a first layer nearly exactly the height set in the slicer. The common suggestion is to print the skirt, then cancel, let cool, and measure the skirt with a micrometer.