do you have any scripts or code added to any of the GP Hooks? Or in a child theme function file?
If not try disabling any plugins to see if one of them is outputing this code.
I’ve just tried deactivating each plugin and trying it but it’s still there. I’m not sure about codes/scripts that I’ve added (sorry new to this and wish I had made a list of everything I had added now!) sorry this isn’t of much help!
Open the browser developer tools buy Right Click > Inspect the live site. Go to Console tab and in errors you will see:
SyntaxError: Unexpected token '<'
This is related to the googletagmanager script that has been inserted. can you disable whatever plugin you used for it and clear any caches you have. And then let me know.