Just update Key to 4.3.108 and CTRL F2 function stopped working in Chrome and Firefox.
I clicked settings in key: / general / autofill / enable system autofill (and restart key) and voila! - the CTRL F2 works now in Chrome and Firefox. But the small sign does not appear.
Sorry for my reply.
But does feature work with system?! or other browsers?
Anyway: with my try to install latest version I can to get situation, when feature will be not work, because there (!? not sure... maybe this is added not just with current release):
--> Two settings/options under UI-settings part:
-> Autofill for system (unchecked with my experience after installation).
-> Autofill for Google Chrome (checked with my experience after installation, but required to install extension).
Do you have something of this settings under UI and does this settings checked? extension is installed?