Hello, kenneth-strid
Welcome to Microsoft Community.
Your Windows Insider is in the Dev channel. To opt out of the Windows Insider Program, you need to reinstall the system. If you don't, you will continue to receive updates from Windows Insider. You can find the steps here:
Leave the Windows Insider Program (microsoft.com)
Here's a video guide for clean installation of Windows:
Windows 11 Clean Installation (microsoft.com)
Remember to back up your files in advance, just in case.
Yuhao Li
Microsoft Community Technical Support