Hi,
Thank you for your report.
I've reproduced the issue in our environment and it really seems to be a bug in current version.
I am very sorry for this inconvenience.
Our developers will try to fix it as soon as possible.
I will let you know (here) when I have any new information about fixing this it.
Thank you for helping us to improve Kentico
CMS.
Regards,
Zdenek