Web Form SOMETIMES Fails

Site URL: https://www.katchmentkleaners.com

I use my own website form on my site to register customers who call on the phone.  I've completed and submitted the form several times and instead of returning to the confirmation notice, the form reloads, empty, and an email never sends.  It's bad when this happens, but at least I know that I need to fill out the form once more and resubmit.  A customer will NEVER know this, and that business will be lost forever.  I have even begun to navigate through a few pages and back to the form before completing it, and still I have observed this failure.  My form is connected to my Gmail and a Google sheet, and neither receive data when this failure occurs, so it's not posting the data.  Can anyone assist??  

Did you ever get help with this?  I use my own form as well.