supportocms
You can try switching default Joomla template on your site -JA Insight to a standard template of Joomla like Protostar and try to edit from frontend again.
If the issue still persists, then the problem comes from Joomla or caused by another extension on your site.
In case that it works, then the issue comes from our template, try to put your site online so we can fix for you.
Regards