Hi PhilTone,
The font size is set to 10em
which is not responsive. Please try to add another value to that. For example calc(10vw + 14px)
value can be a good start, and then you can play with the numbers to find the best case scenario.
Please do not use the Responsive text feature as it is using the Javascript code and you already use the headline element which you can easily set a responsive font size as I mentioned.
Please read the reply below to know more about the way the value I suggested works:
kindly get back to us with the result of the steps above and URL/User/Pass of your WordPress dashboard using the Secure Note functionality of the post to follow up the case if you still have problems.
Thank you.