wolftech could u please check if there is some bug?
I can confirm this is a bug, although it only seems to affect Safari browser. I will look into it and have it fixed for next release within 1-2 weeks.
In the meantime, if the issue is critical, you would instead need to use Javascript config option click_window: ['pdf']
, so that PDF files open in new windows instead of in the modal (where the issue occurs).
Sorry for any inconvenience.