Why is the mobile menu not functioning on Dawn theme?

[BAFC]

SOLVED

Updated to version 11.0, but will need to add back in the custom changes. 

Hi,

The menu on my store is no longer working on mobile.  It works fine on desktop. 

Theme is Dawn, version: 9.0.0

It was working fine until yesterday, but today I when I click on the menu selector, the menu does not appear? 

I have not changed anything since yesterday that would affect this? 

Can someone please advise on what this may be and how to rectify? 

The url is: www.bafurnitureclearance.au

Thanks in advance.

Regards

BAFC