Hello,
1) I don’t see the issue with the off-canvas mini cart while adding to cart https://gyazo.com/122cb7a90c4cac35ed51cf96d50a1f7e
2) Mobile menu also works fine https://gyazo.com/8b0fee2e9b74f18d1f71616c3f017611
Clear the browser cache and cookies.
Regards