Image caption freezes in Casper theme

I’ve been using Ghost for nearly four years now and I really like it. However I find that the image caption box often freezes. I write a caption underneath an image and then often we I return to edit the caption it has frozen and can’t be changed. Is anyone else experiencing this problem? Does anyone know know how to rectify the problem. Anne

Yes, I’ve used Casper for over a year (also very happy) and this has happened at least a dozen times.

At least it’s not something I’m doing wrong, Any ideas how to rectify this?

Sorry no, I’m a user but not a coder.