The calendar is not translated in the web form

Hello everyone!
I have a problem with the translation of the calendar - it is not automatically translated in the web form.
image

At the same time, everything is fine in the doctype itself and the calendar is translated.
image

The system language is Russian, the user’s language is Russian, but the calendar in the web form remains in English.
Please tell me what could be the reason and how to fix it?

Oh, screenshots should be the other way around. I hope you understand.