unnecessary vertical scrolling

i have a problem – there’s an unnnecessary vertical scrolling happening on my website that’s running on Mercury theme, that is no observed on the live preview of original theme.

https://travelmolecule.com/galleries/test-album-1/

versus

https://themes.themegoods2.com/mercury/galleries/gallery-carousel/

i beleive it may be due to script conflicts between theme script and plugin script? however, i have already deactivated all my plugin script but the problem still persists. any advice? thanks,