Windows 11 keeps changing my default browser back to Edge after every update

Since you have already selected Chrome repeatedly, the useful next step is to establish whether Windows actually changes its associations or a particular application merely opens Edge. Immediately after the next occurrence, open Settings, Apps, Default apps, select Chrome, and inspect the HTTP and HTTPS link types as well as the browser default. Record what changed and the update's KB number. If this is a work-managed computer, ask the administrator to check the default-associations policy: Microsoft documents that managed associations can be reapplied at sign-in. Do not edit the registry or try another Edge removal to work around an organizational policy. On an unmanaged PC, compare the behavior in a separate user profile and test a normal web link from another application. If the associations themselves revert, report that reproducible sequence through Feedback Hub with the Windows build, rather than assuming every update intentionally resets browsers.