Can't save value for title field inside Repeater field

[PawelGIX]

Short description of the issue

This is Title field inside repeater inside ProFields PageTable
Only title in the repeater field is not saved. For example, the short_description field works fine.

Repeater is here:

scrnli_11-10-2021_19-48-22.mp4

I checked the post data, the field is being sent to the server.

• ProcessWire version: 3.0.184 © 2021
• (Optional) PHP version: 7.2
• (Optional) MySQL version: 5
• (Optional) Multi Language website with one language right now.

[PawelGIX]

Saving this field started working when I changed the field to plain title.

Update:
It seems the problem only occurs when there is one language in Languages.
As soon as I added more, it started to work.