HELP: widgets duplicate and override each other after saving

Hello,
We have faced an issue, that:
We go into CMS page and make some changes (doesn’t matter if it is 1 or 10 widgets page, either it contains images or text only)
We press save button
Sometimes some widgets duplicate and appear instead of other widgets (this way we loose content and specific widgets)
After that we press save again and again
Widgets keep duplicating and overriding other widgets without even making any changes in the content.

This is how it looks before making changes and saving: https://imgur.com/ojzlMlb
This is how it looks after: https://imgur.com/CMmTsJo (banners widget doubled and appeared instead of product list).

But this does not happen each time, sometimes it happens, sometimes not.

Maybe someone has experienced such situation or has any ideas how to solve it?
Me and our programmers does not even know where to start fixing this. Any help would be really appreciated.
Thank you