Background:
Microsoft has been progressively increasing the security measures in Windows, and disabling insecure guest logins is one of those steps. Insecure guest logins can pose a significant security risk because they allow access to network shares without requiring a username or password. This change aligns with the security enhancements seen in Windows Enterprise editions.
Your Situation:
After updating to Windows 11 24H2, you found that connecting to network shares without requiring a login (everyone access, password protected sharing turned off) no longer works. Shares with a password and those configured in group policy to allow insecure guest logins function correctly.