Delete Entries will delete WordPress Pages

Hello!

Currently, the page in question is a staging website that is not yet online.

The situation is as follows. I have a “Send Inquiry” form (Formidable) that is visible on several pages at the top of the page. In this form, visitors can enter the date of arrival, departure date, number of people and are then forwarded to a second form under the menu item “Contact” in order to enter further data.

For test reasons, I have made a few entries in this form on the various sub-pages.
Today I wanted to delete these test entries. However, all subpages of WordPress on which this form appears were also deleted.

Please help what may be the cause of this.
Thanks in advance.

The page I need help with: [log in to see the link]