I have never seen this issue before, so I don’t have an answer but with some basic troubleshooting we should be able to find the cause and investigate how to resolve this.
The first step is to find out whether this is caused by a possible conflict with another plugin or your theme with some temporary troubleshooting steps
Does this still occur when
1. all other plugins are deactivated
or
2. the theme is changed to twentythirteen.
Thanks for the quick response!
1. still happens with all plugins deactivated
2. does not happen when the theme is changed to twenty thirteen
This result suggests that there is a conflict with the theme..
Had this occurred with one of the free themes hosted on WordPress.org, I would have been able to install the theme on one of my test sites to investigate, however I don’t have access to your theme’s files so unfortunately I cannot do that.
I have not heard of this issue occurring with any other theme, but I suspect it is caused by an conflict with a jQuery script, but it could be a simpler CSS issue. Your theme loads a lot of js and css files. By temporarily preventing these from loading one by one it should be possible to identify which file is causing the conflict. Can you ask your theme vendor for the best way to temporarily remove the scripts being added by the theme to enable you to troubleshoot whether this is the case – there should be a way to do this programatically, but there may also be options in admin for this.
