There seems to be a glitch in Enpass, where it doesn't lock during System Lock (Win-key + L) even it the setting is applied as shown below.
The bug occurs (for me) only if I initially unlock Enpass through the Helper Window in System tray.
If I initially unlock via the main Windows, the "System lock" works as expected.
Enpass 6.7.4 (934)
Windows 11 21H2
Fulltime Windows Hello-activated