My wife has a paint & wine party business and I've been using an embedded Google Form for registration on her site for nearly a year without issue. Last week I updated the photos in the Registration section and after that my Google Sheet has stopped getting updated upon submissions.
I thought it might be that I accidentally deleted an extra <div> or something, so I tried a backed up version of the registration page and that's not updating the google sheet either. The registration page is this big mess of html code which would be way too much to post all here so let me know if there is a specific important piece of the form that I should provide.
The registration portion of my wife's site is mixituppaintingparties.com.
EDIT 1: I embedded the Google Form into my page using the Sneaky Sheep tool because I wanted to redirect to PayPal upon submission. It's worked fine since March.
EDIT 2: I noticed that if you submit directly from the original form it does update the google sheet just fine.
Best Answer
The OP added that he used Sneaky Sheep which apparently takes the HTML from a respondent Google form and delivers HTML files.
Every time that the original HTML from a respondent Google Forms, due to a change made by the Google form editors or due the HTML output generated by Google, the HTML files should be generated again.
It's worth to say that:
AFAIK, editing the respondent Google form is an unsupported feature (in other words a hack), so any change done by Google that affect this could not be proactively announced.
Users of Sneaky Sheep having issues should consider to share to its developer and community of users your relevant findings.