Mipmapping behaviour differs significantly between hardware

I noticed a big discrepancy between some mipmapping issue reports which point to significant differences in behaviour between hardware.

Exhibit A:
- A report by an user with an AMD card (Radeon RX 7800 XT): MC-303462
- Copper & Iron Bars become increasingly more opaque with higher mip levels

Exhibit B:
- A report by an user with an Intel Arc card (Arc B580): MC-303453
- Copper & Iron Bars become increasingly more transparent with higher mip levels

Reproduction Steps:
- Observed the behaviour of iron bar mipmapping
- Compare the behaviour with an user on different hardware

Observed Results:
- The observed behaviour differs significantly between users

Expected Results:
- The graphics would be consistent on different hardware