FLOOD
Thanks for your answer!!!
Settings -> General -> Autosave and autofill -> Loggins and passwords ALREADY selected / checked
2nd try: Same setting first unselected, then selected, problem still persists, key is still grey
https://moodle2.ugd.edu.mk/login/index.php
Cookies are already ENABLED for that site
The only difference from the last time is that now the key icons are shown in the fields.
In both cases, nothing happens when i click on the icons, not even showing "Filling out loggins and passwords is disabled in application settings".
No settings were changed in Firefox and KPM, this problem came ONLY with the newest Firefox v67.0.3(64-bit).