Responsive drop down menu not working

Hello again!
1) On tablet and phone (IOS), the drop down responsive menu is inactive, when you click on the symbol (image attached) no menu appears.
2) The drop down menu symbol is also appearing on the full screen version on the computer monitor (also unresponsive when clicked on). Is it possible to disable and have it only appear on tablet and phone?
Thanks for all your help,
Kim

The "hamburger" menu is a module position calles >> offcanvas
You can disable this module and then it is in-active.