Is this in Rhino 7 or 8? I have a similar issue in Rhino 7 for one of my display modes. The only way I can get the grid to disappear is to turn off the Cplane axis.
What I noticed is that the grid inherits the background colour.
It’s fixed in Rhino 8, and I was told that it won’t be addressed in Rhino 7, which makes sense.
Dan
It is in rhino8.Thank you for sharing this.