@nicoleorriens
Yes, you are correct that the menu works in desktop but the hamburger ≡ does nothing on the mobile sizes. 🙁
You will need to check for sure which plugin is causing the issue, by turning them off one by one and testing. (You don’t need a phone to test, just narrow the browser until the page goes into the mobile state and the ≡ hamburger appears.) It should only take a few minutes as you have no caches to clear.
When you have found the problem plugin(s), you will need to write to them and explain the problem and ask them to fix it.
That may take a while, so you may need to change out the plugin with a different one in the meantime.
Plugins should not be causing such issues with a theme.
Finally, though you say you have no cache installed, do you have any optimization plugins? Any optimization of Weaver CSS or JS will cause such unpredictable issues.
Regards!