Form is not working when my client hit the Submit button

I have a few clients trying to register for mini sessions but when they hit submit, the form freezes/gets caught up and doesn't complete the registration process. Please advise. When "submit" it hit, it just says "please wait" and doesn't do anything from there...

unsure why i am not receiving replies to my thread when others around me are? 

I cloned your form and I removed the payment integration field. After hitting the Submit button, I was redirected to the Thank You Page. Here's a screen capture:

May I ask if this form is embedded on a webpage? If it is embedded in a WordPress webpage, then please try re-embedding it using the iFrame method. Here's a guide: Getting-the-Form-iFrame-Code.

If the issue persists, let us know. Also, please share the URL of the webpage where the form is embedded so that we can further investigate.

So am I not allowed to use the payment integration option on the free plan? 

You can use the payment integration on the Free plan. The screenshot I've shared is the cloned form without the payment integration. May I ask if this form is embedded on a webpage? If yes, then please provide the URL or link to the webpage so that we can test it.

We'll wait for your response.