Domoticz

I have a strange thing I'd like to check with you guys...
I have installed Domoticz with the Jadahl-package on my Syno. The first time I went to the settings-page (to add location and email-server and such) The password-fields on the tab "System" were empty. I did not enter a password in any of them either.
But when I go to the settings-page again, a lengthy password is present in the password-fields under the items "Website protection", "Light/Switch Protection" and "Security Panel".

Does anybody know how and why this password is created? I've set my router to not forward requests from outside, so I do not need a password as far as I know.

-- EDIT --
I've tried to delete the input in the password-fields and applying the changes, but when I return to the settings-page the fields are filled again...

This one stills bugs me a little bit, so I removed the passwords from the sqlite-database manually. The settings-screen confirmed that the passwords were empty by displaying empty form-fields. I did not change anything in the settings and hit "apply". When I returned to the settings-screen the passwords were filled again.

After this I decided to try if it was a firefox-plugin or anything. I deleted the passwords again from the database, and launched Edge. I never use Edge, so it has no settings or plugins or anything. I went to the settings-page again (and the password-fields were empty), hit apply without changing anything, and when I went back to settings the password-fields were filled in again.

Does anybody know if this is normal behaviour for Domoticz, or if I am dealing with a bug here?

Hello all,

I've just upgraded to 4.9700 (I know, I'm a bit late to the party, but I had some issues upgrading from Jessie to Stretch, but all is OK now), and I thought I would check this again.

And sure enough: there are passwords filled in in the settings-page. I never created any kind of password for Domoticz, as it is running within my private network and is therefore not accessible from the internet (except through VPN, but if that happens I have other problems than someone switching my lights on or off).

Are these built-in passwords, or something? And if so: what are they, and when should I need them?