Missing H1 tag on product page

I need help trying to find out why the h1 heading wont show up on the product page. I noticed it when i installed an "inquiry" module on the product page and saw that H1 headings would show for the most recent extensions on the page instead of the product name. Now that i've seemed to have fixed it, the product name wont show.
https://mobileunlockbase.com/zte-not-found example

thanks

It seems that the issue is due to the module, please check your logs.

As above, it must be the extension so contact the extension developer.