I keep banging my head up against being excluded from using sites like Channel4 (UK) because there is no way to have java work!! Must I migrate all my browser traffic to edge? You seem intent on excluding anyone who doesn't code from your products nowadays.
I am able to access the Channel4 site without a problem. To help us to look into this matter for you:-
Which add-ons do you have installed in Firefox?
What level of tracking protection do you have set?