Ninja Forms: No Submissions after sending form nor any email is received

Hi,

I’m having a hard time fixing a form that is not getting submitted whether with or without ajax.
https://www.accord-worldwide.com/request-for-quotation/

And I have no idea how to go about it.

Similarly, our website for a long time now will not open any page without an ending /
and any sitewide search functionality is also never working.

any ideas what can be wrong here?