Form submission data blank!

Help! Just realized the form on my site wasn’t working properly – when users clicked “submit” it just said “processing” and nothing further happened.
When checking submissions in WordPress, there are multiple submissions there – but all the fields are blank. How can I recover this data? Even if the forms weren’t properly submitted/executed, is there a way to view the information that was provided?
We have taken the form off the website and replaced it with one from another system, so I’m not trying to find out how to fix the form going forward. All I need is to find a way to recover this data and not lose my leads.
Any information that can help would be so, so appreciated.

https://wordpress.org/plugins/ninja-forms/