Error: "We could not process your request due to malformed syntax", when trying to delete a form
Regarding the issue of forms delete it occurs because of installed browser extension (plugin) 3CX phone. It automatically modifies pages by adding its own elements/code so it breaks pages functionality and leads to this error. Please try to turn off the plugin or open the browser in Incognito mode (where most extensions are disabled) to confirm the error doesn't occur.
How to open Incognito window?
For Windows, Linux, or Chrome OS: Press Ctrl + Shift + n.
Mac: Press ⌘ + Shift + n