Can'T Using Glass Bed, Z_offset(?) help

[ugryy]

Hello there.
I want to use glass bed with my 5m pro. I found a clip that doesn't interfere with bed leveling and toolhead.
The problem is when I tried to bed level, nozzle wants to dig into bed like the bed is still pei sheet. Glass bed is 4mm, at Z 3.3mm nozzle barely touches to glass and etween 0-0.2mm (Z) with pei. I tried to change probe z_offset in printer.cfg to 3mm from -0.25 but didn't work.
Which setting should I change? I need glass bed because I need mirror finish on bottom.
And if there is a way to add this setting to orcaslicer printer startgcode, that would be awesome.
Thanks!