@NomadicMoonArts
I don't know anything about Firefox. But is your browser updated? (Etsy has stopped support for older browsers).
And if you are using the App (I never have), but I've heard it can be glitchy. Maybe you could try a browser instead.
(You've probably done this); cleared cache, cookies; unplugged and restart modem.
I hope something works for you. In the meantime I'm going to see if my Orders Page loads (my Shop is on Vacation, so it would be from last year). I'll come back and let you know. (I always use the same desktop computer, Chrome, Windows 10). Be back.
ETA: Yes, mine loaded (I selected "Completed Orders").
I hope something helps you. Good Luck.
