Our site is set up to access through a CDN.

When a WFFM Form is submitted with image sizes of 3MB, it returns a "413 Request Entity Too Large" status error.

I have found, in online documentation, that this error may suggest a file upload limit of the CDN, but our hosting provider has told us that it is a result of too much information in the Request Payload headers from the WFFM submission. He has recommended that we try to trim the headers on form submission requests.

i.e.

Does this sound like it could be the issue? Any details to help explain the issue or to help with actually trimming these headers would be greatly appreciated.