I just started using Travelify and am playing around with it on my own server before moving it to the final destination. I love the theme but have come across one strange error.
After opening an image in WP lightbox 2 and then closing it again to continue browsing, I suddenly have the menu bar not only as menu bar, but also as a dropdown right next to the menu bar.
Some JavaScript from your lightbox plugin is conflicting with JS included in the theme and there is not much you can do it unless you are JS expert. Personally I would recommend to use JetPack plugin to get results like I have in my theme demo: https://colorlib.com/travelify/post-format-test-gallery/
It is much better coded plugin that one you are using and there are no conflict with my theme. Plugin you are using is very slow and it uses around 9 javascript files which is insane for what it does and I strongly recommend to keep away from it when possible.