submission form: some labels not translatable?

I have problems in translating the below labels in submission form

I searched for those labels in submit form "default" template settings, they are not there

I can see that those labels appear in cobalt english language file

and also I can see that they appear in cobalt italian languae file (already translated)

but in submission form I still see them in english language

I am visiting the site in italian language

I also changed my user backend and frontend language to italian, just to be sure... then logged out and logged in again

those labels are always in english... any idea why this is happening?