Hello,
Your issue is a JavaScript temporal issue.
There is a function which init the "nameboxes", which is added into the page header.
There is another function which init the characteristic system, by setting some values (callback URL) to the characteristic namebox.
While the function are right seen in "order", in the page they are not called with that same order.
So the second function want to initialise the callback on the namebox which is not yet initialized.
That function do not trigger any error but, by not seeing the namebox, just do nothing.
One solution to try is to change the line
window.Oby.ready(function() {
By
window.hikashop.ready(function(){
In the file "components/com_hikamarket/views/productmarket/form_charasteristic.php".
If it does not solve the issue, we would need to add a fallback delay system.
Regards,