Wife's PC on Release Preview keeps updating to Dev

My wife's PC, which is fully compliant with Windows 11, is on Release Preview the same as mine. Couple of days ago it suddenly updated to the latest Dev version unprompted. Had to restore it from the Macrium dump, but it then tries again. The Windows Insider page is occasionally looking like this after booting



Although logged on with MS account top left, the same account has not been linked in the Windows Insider. Hence it appears her PC defaults to Dev mode, which is good enough for WU to install the latest Dev version.

If I click on Link an account for the Insider account and select her address it immediately updates to this -



But by then it's too late as WU is already doing the Dev update.

So if WU finds the Insider account is not linked, why does it go ahead and install the Dev version?

Wife's PC specs are the same as my System One, except the motherboard is an H510M.

Exactly the same thing is happening to me on one of my computers. The Insider Program is horribly messed up.

This issue has also been reported here. No obvious solution just yet.

I have the same problem here. It has a watermark (Insider Preview Evaluation Copy) on my desktop and unable to remove it, lol

Her PC has a copy of Office 2016 installed which I purchased in 2016 using an MS account I no longer use. But the licence is tied to that MS account so I have to keep it live. This means there are two MS accounts on her PC. I have removed this old one to see if it fixes the problem. Office 2016 is now complaining that there's an "Account Error" that needs to be fixed by signing in to that old account, but all applications are working and Office is still updating. So I'll leave it like that for now.

I have also logged on to that old account and deleted her PC from it. It's also not registered as an Insider account.