No problem accessing either site on Firefox 80.0.1 (64-bit), but you don't say what version you are running.
Have you tried running firefox with Add-ons disabled ?
If it works any recently added extensions ?
Thanks for your reply much appreciated.
I am using Firefox 80.1 (64 bit) same as the one you're using.
If I disable Avast online security extension no problems, loads perfectly.
With it enabled takes about 2 seconds to load correctly.
I have had this problem for a while, as it was more of a nuisance then anything else.
Finally I decided to see if anyone else had this problem, I thought it must just be me as I haven't seen any complaints any where.