FormSpark Failing with SSL Error

I have a simple form on page for support requests that POSTS to Formspark. It is failing with :

[Error] An SSL error has occurred and a secure connection to the server cannot be made.

[Error] XMLHttpRequest cannot load https://submit-form.com/xxxxxxxx due to access control checks. in both Chrome and Safari.

I can use POSTMAN and submit a form successfully.

I can successfully curl a form from the servers that are getting the issue.

Any insights are greatly appreciated !!! My code is as follows:

 let data = {
        name: name.value,
        email: email.value,
        message: message.value
    };

// Stringify the data into JSON format
    data = JSON.stringify(data);

    console.log("Data: ", data);
    axios
        .post('https://submit-form.com/xxxxxxxx', data, {
            headers: {
                'Content-Type': 'application/json',
                'Accept': 'application/json'
            }
        })
        .then(() => {
            sent.value = true
            resetForm()
            startAutoCloseTimer()
            console.log("After Split: ", currentDate.toString());
        })
        .catch(() => {
            //console.error('Error details:', error);  // Make sure to capture the error object
            loading.value = false;
            alert('There was a problem sending your message.');
        })
        .finally(() => {
            loading.value = false;
        });
    console.log("last Split: ", currentDate.toString());