Follow-up intent not possible to create in DialogFlow

[Lukas3]

Hi, I am trying to create a Follow-up intent in DialogFlow but when clicking on Add follow-up intent, notihng happens, just some empty frame appears. Please see the printscreen. I tried it on another PC but the result was exactly same. I am using Google Chrome.
Do you have any idea what could be wrong, if it's on my side or is there any bug on DialogFlow side?

Thank you
Lukas Jezek