The default transparency for the command window seems to be set at 70% when it is 'floating, not active' above other windows. I'm trying to disable its transparency entirely. I know it can be set on a one-time basis by clicking on the wrench, but there doesn't appear to be an option to set the default.
Works fine here (it stays set at solid/no transparency) after the program restart if I understood what you are asking for: AutoCAD2022.1.1 in Windows10Pro.
Walks us through what you are doing step by step, click by click, when you can, let's make sure we can follow your actions. Or post a video.
You should set the transparency via the wrench as you describe, and then save the workspace. In my experience, you may need to adjust this, as well as other settings, multiple times before it finally sticks. It's just buggy behavior of the software.
