Render Output Pixellated

Does anyone else have this issue? When I render my project, the output is pixellated.
This is for both H.264 and H.265 codecs. When I render the project using DNxHD, the output is fine.

h264output.jpg (427.83 KiB) Viewed 234 times

Also (perhaps a small detail)- In the Delivery Tab, when I select YouTube or Vimeo/Twitter, I am seeing the Render settings for the Master H.264 (and not the simplified settings).

Resolve 17b6 Linux (Pop!OS) | NVIDIA 2080
QuickTime or MP4 | H.264 | Max Quality 10000Kb/s (output pixellated)

Any help is much appreciated!

Rens

I've never seen anything that bad coming out of Studio for Windows.

I have seen occasional encoding artifacts when my source material is H.264.