I’ve seen a few threads on this topic but never got a sense that they were resolved in many cases.
I had this problem occur suddenly today on a camera that had been in operation for approximately a year. Nothing I could do, even a clean setup would let it connect once I moved from my “setup” location next to the router, back where the camera is mounted outside.
Fortunately I had a new spare on hand, so was able to do some diagnostics by elimination. Ultimately, what fixed the problem was replacing the little Wyze power brick that powers the camera.
Even the new camera had the same failure to connect/unstable connection error when I moved it from my “setup” location to where the original camera had been operating for the past year. That was while connecting it to the original power supply.
The original p/s appeared to be working, the red light would appear on the camera but seldom did it go further. Occasionally, it would go to the blue/red light but normally it just stayed a solid red.
The only thing I hadn’t done was put the new power brick in place of the original. Once that was done, the connection came up immediately.