How does the z work on this printer?

I’m staring to notice a few things here that prove the leveling or adjusting of the z offset does not really do anything,

  1. if my prints are not “squishing” the filament when printing, lowering the Z does not help.
  2. when printing, it shows .3mm if I change the offset at any time this is not effected.
  3. Using the save or not, does not seem to make any difference.
  4. The printer acts like it level every time before it pints anyways. Do I need to turn that off some how?
  5. If I add a washer between the tip and the block to intentionally offset the Z in a bad way, I can not correct the issue by adjusting the z using the leveling process.

It’s like this process does absolutely nothing.

I am just starting this hobby myself, but wouldn’t that be controlled in the slicer?

I wondered that but I do not think so, the settings are saved in the m503 command (eeprom). And if you hit save from the printer, it changes them in the eeprom. If it is in the slicer, then where?