Web app doesn't show or play scores much of the time

I'm a late-beginner/early intermediate piano learner who uses the website exclusively to display, play and download public domain scores. Much of the time - and more and more - when I open a score it shows only the first page and when attempting to play, does nothing at all. The attachment is what shows for everything beyond page one.

What's the problem with this? I have a paid subscription, this is the entire reason I started using this site, and if these features aren't available it's totally useless. I'm also a long time IT developer/analyst and this is totally amateur hour for this stuff - this kind of unavailability of basic functionality would be fireable anywhere I've worked over decades in this.