Is this weirdness happening for everyone, or just us?

[brandon.foster]

Sounds like it might be related to this bug?

8.42 Release Notes

8.42.0.572 (Wednesday September 14, 2022 ET) Bug fix: Fixed an issue where using None for the background or text in formatting rules could result in non-readable text in the grid (especially when dark mode is activated). [SG-24897]