When you have this type of problem with your interface, please try to start Firefox with all plugins disabled.
Firefox: You need to go to your browser in Settings click on the help menu.
A menu will appear click on “Restart with menu Add-ons Disable”
A window will pop up and press “Restart”
Another window will open click on “Start in safe mode”
Now you should re-open your interface and the problems should disappear.
If not please open a ticket on Zendesk.