Check that the phone you carry is paired over Bluetooth. Open Settings → Accounts → Sign-in options → Dynamic lock and turn it on. Test while the PC is idle and the phone is away from it. For an immediate lock, press Windows + L.
01Confirm Windows recognizes the phone you carry
Section linkTurn on Bluetooth on the phone and the PC. In Windows, open Settings → Bluetooth & devices and check whether your current phone is paired. If you switched phones, add the new one over Bluetooth. Return to Dynamic lock in Sign-in options and check whether Windows now recognizes a paired phone. If a managed PC does not let you change the option, ask its administrator.
02Test with an idle PC and the phone out of range
Section linkLeave the session idle and take the paired phone away. A nearby room may still be within Bluetooth range. Ask someone to look for the lock screen without touching the keyboard or mouse. Microsoft says the feature needs both a drop in the phone’s Bluetooth signal and an idle PC. Someone using the PC can prevent that test from working.
03Check the lock screen and keep a manual fallback
Section linkA dark monitor by itself does not show that your session is locked. Check whether Windows asks you to sign in when you return. If the test still fails, lock with Windows + L when you step away. Use that shortcut whenever you need the PC locked immediately, even if Dynamic lock worked in your test.