I have had my 5 S1 2 days. After I assembled it, I printed the rabbit file and it worked perfectly. I installed the Sonic Pad, performed all the bed leveling and auto calibration per instructions and now the Z axis is either too close to the nozzle or too far away. I cannot seem to get the right settings to make it work correctly again.
I feel your pain. I was pulling out my hair because I had several good prints, and then one print I was doing went from breaking free halfway through, to going off the rails right at the outset. (Instructions are really terrible, whether in the manual or on YouTube) This is what I figured out, and it seems to work for me on my Ender 5 S1 with Sonic Pad.
(Do all this after pre-heating nozzle and bed. After every reboot, immediately heat up again)
First step: Tighten all the wheels down all the way. Then do the probe calibration and adjust the Z until you’re scraping paper. Then, and this is the part I don’t get why I have to do this, but I lower the bed (increase Z) about 0.65 mm. Hit OK, the pad will reboot.
Second step: manual leveling, all four corners scraping paper. If I didn’t lower the bed in the previous step, the nozzle would be hard against the bed in this step.
Third step: auto level. I’m not sure what this tells us or even if we need to do this step if we’re sure we did the previous step well. Does it tell us if all the test points are within tolerance, or if the bed is too badly warped to do a print, or what? (Again, I haven’t found documentation that doesn’t suck.)
Fourth step: do the probe calibration again until you’re scraping paper. Hit OK, reboot. You should be ready to print now. (This is the part I was missing.)
After this, you should only have to do steps 2 - 4 for awhile. (Don’t ask me why I don’t have to lower the bed in the probe calibration again before doing the manual calibration. This doesn’t make sense to me,)
I figured this out after remembering that I had to do something similar with the Ender 3 (with Marlin): after leveling the four corners of the bed I had to go back to the center and adjust. I hope this helps.