Since Windows 11 24H2, Device Encryption automatically turns on when you clean install and sign in with a Microsoft account. This only affects fresh installs or new PCs with 24H2 preinstalled—not ...

If you see This PC doesn't support entering a BitLocker recovery password during startup, enable WinRE, tweak Group Policy, ...

Then re-enable BitLocker via Control Panel > System and Security > BitLocker Drive Encryption > Resume protection. Note: Suspending BitLocker, even temporarily, should be done with caution.