I also have this issue. Lightbox loads fine on desktop browsers, but not in mobile browsers (iOS, Chrome + Safari). When clicking on a gallery group icon, I am taken to a gallery page with images from that set. When I click on any image, I am taken to a page (sitename/wp-content/uploads/photo-gallery/imported_from_media_library/dsc_1234.jpg?bwg=1590287302) with the image shown. I’m able to Copy, etc. by long-clicking on the device screen. When I click the “back” button, I get a faded backward-spinning circle.
I’m able to access https://website.com/wp-admin/admin-ajax.php?action=bwg_frontend_data without issue on both desktop + mobile. It’s a wall of links that are clickable on both devices. As a wordpress noob, looking at your documentation, I seem to have gone down a admin-ajax.php rabbit hole. It appears that may be the issue?
Funny thing is, I was able to get this to work once on my mobile device and then a few hours fly by and I can’t recall for the life of me how the universe was aligned to get it to work the first time.
Much appreciated.