I can't expand one of my topics in my mind map

There is a glitch in my online version that I just purchased. I created a mind map, but for one of my topics, it won't allow me to expand and edit the information under that topic.

Please fix or advise a work around for me.

(I've used the business version at work for many years, so this is just so disappointing in the personal / online version. And to happen to me within the first 2 hours of paying, downloading, and starting my first mindmap.)