Pinterest Settings not saved

Did you save a post after changing Pinterest settings?

Of course

How can we replicate it exactly?

I just tried to go to one of the existing posts.
I changed Pinterest board and “Message format”.
I saved the post.
After refresh, my saved changes are still there.

Is there a way where I can send you some credentials, so you can look directly into my backend?

Sure, please open a support ticket here: https://www.nextscripts.com/support

Alright, I created a ticket a few seconds ago.