Same for me.
Running MacOS 10.14.6 and Enpass 6.6.2 on a MacBook Pro 15 (2016). TouchID feature in Tools/Preferences/Security is checked but grayed out and a message (in Frenhc) like "TouchID is not activated on this device".
Clicking on "More..." does not help at all : you should display a temporary messagebox about this bug as you are aware of this. I searched for days before finding this thread.
Added a new fingerprint to see if the issue was more on MacOS side but did not helped.
Need to use NIP feature (in Tools/Preferences/Security) in the meantime.