Thanks for trying. I'm sorry it didn't work.
The good news is that Juicebox galleries do work with "Enable HTTPS-Only Mode in all windows" in Firefox on https:// sites.
One thing I notice is that at the foot of your gallery page, you have some Statcounter code which includes a couple of http:// links (not https://) in two separate <noscript> sections.
Try changing them to https://. Maybe this is breaking the page in HTTPS-Only Mode.I'll keep my fingers crossed that this helps.
This did work! Thank you so much for your patient troubleshooting, especially since it was our own error of not having the updated https statcounter code on the page. I really appreciate it. ⭐⭐⭐⭐⭐