On a new install of JetFormBuilder (v3.5.1.2), the "Request Key" was randomly generated as a numeric-only string (e.g. 382729). This caused forms to fail on submission — no data was processed or saved.

After troubleshooting, we discovered that changing the Request Key to include letters (e.g. a38272 or req1x9) immediately resolved the issue. Switching it back to a numeric-only key consistently broke submission again.

Steps to Reproduce

1. Perform a fresh install of JetFormBuilder.
2. Set the Request Key to a numeric-only value (e.g. 123456).
3. Submit the form.
4. Notice that submission fails (no data is processed).
5. Change the Request Key to include at least one letter (e.g. a123b6).
6. Submission works correctly.

Expected Behavior

Form submissions should work regardless of whether the Request Key contains only numbers or a mix of characters.

Actual Behavior

Numeric-only Request Keys break form submission.

Suggested Fix

• Ensure that newly generated Request Keys always include at least one letter
  or
• Update the validation logic so numeric-only Request Keys work as expected

Edit:
Additionally, no error was being shown front-end. The network request of the submit returned the full HTML of the page the contact form was on, causing the error handling to fail. There should be a generic fallback error message.