This is an old issue that keeps occurring. I've seen older posts about it here but they seem to have other causes.
In my case, it appears only once, only when the Solo2 is started up (or fully restarted), and only when the first channel to be opened is an encrypted one. Using a Tivusat card+CAM.
If I then switch to any other channel (encrypted or not) it will work normally and the issue will not reappear until the box is shut down or restarted.
The attached is from an older image, but issue still occurs on 2024-06-09.