Thanks Brett, I wish it was a technical problem on my end. That was the first resource I checked but unfortunately there is some major problem with the system which input ld+json Structured Data script into the pages. I tried it in all my other clients accounts and the problem is not just local, but system wide.
I then contacted support to let them know about it and they are now investigating with the code wizards what is the problem and why the Structured Data script submission box do not accept scripts.
At first I thought it might be a code issue on my end but even if you take all the code out and just leave the script tag without any actual code in it, the submission will not go through. (see screenshot below)
