Forms stopped working on all sites

Everything has been working fine for over a year and suddenly today all forms on all sites after you hit submit goto a Cloudflare bad gateway error 504. The form results are still stored and we get a copy sent via email but the user thinks the form didnt go through and contacts us to tell us or repeatedly submits the form. Here is an example:

My host said: There seems to be an issue with Cloudflare, as the contact form times out only through their CDN. I’ve tried pointing the domain locally directly to our servers and the form submission was successful:

Really need to get this resolved and appreciate your help.