Hamburger menue icon not working in Firefox?

Hi, is this just a bug in my Firefox install (51.0.1 (64-Bit), Linux) ? On the demo site (https://demo.gavick.com/wordpress/writer/) the hamburger menue icon is not working, how come? Can anyone check if it is working at all on Firefox? Thank you very much.

Hi,

I've checked Firefox version 51.0.1 (64 bity) - OSX and can't see any issue with the hamburger menu.

Hi,

I've checked Firefox version 51.0.1 (64 bity) - OSX and can't see any issue with the hamburger menu.

Ok, thanks, so it's most probably a problem related to my Firefox Linux Ed. Thank you very much.