Menu offcanvas collapsed

Hello,
I have a problem with the Offcanvas Menu.
It dosen't work on different pages
The Menu ist empty.

In the Backend I used the Menu Assignment "on all Pages"
It would be nice if you will help me to solve the Problem.
I use I-Phone 10
You can also see the Problem on my Website www.tierarztpraxis.kalkuhl.de
Meik

Hi there,
the Url is not right!
Please do not post your question to a solved thread.