Invalid argument supplied for foreach()

Browser: any
OS: macOS
URL: staging environment

hi guys. i got a horrible old website moved to staging. i have just started creating a cpt with a couple of custom fields using metabox, and i have this error.

Warning : Invalid argument supplied for foreach() in domain.com/wp-content/themes/bricks/includes/integrations/dynamic-data/providers/provider-metabox.php on line 379

only in the backend, and only in pages using metabox with a cloneable date picker field. no errors if not cloneable.
also, and this is maybe more a metabox issue, i cannot change the date format. no matter what i specify, it will always display yy-mm-dd, like 2022-12-05. no luck to change it to dd mm yy, to have 05 12 2022.

all works fine in the frontend but this warning is… worrisome?
the cloning feature may be helpful for multiple dates events, but i can manage to tell my client that no, he cannot have more then one date for an event in the same post.

maybe all of that is not a bug.