Post processing depth buffer is offset by half a pixel if MSAA enabled

This is weird to the point that I don't know if it's some kind of driver thing or not, but it's breaking one of the features of my post-processing AA shader.

The offset is only vertical, not horizontal. 4x MSAA.

openmw_2023-02-03_21-42-29

openmw_2023-02-03_21-42-30

What it should be like:

openmw_2023-02-03_21-43-30

Windows 10, AMD RX 480 8GB, drivers last updated at some point in the past few months, very recent nightly build.