This is a odd one. i know it has work before , i have use Firefox for many years. so something most have change this.
its not that the speed is lost is more a Firefox just sho or think it is. ( Browser issue only. ) https://www.speedtest.net/
Work fine with chrome and MS EDGE and MS app store. with sppedtest from
and i know it did work from the past, because i know i have tested with it, but i bet a update or something cause Firefox to do this.
the bandwide is there , its just Firefox that half the speed in the Browser. this is not even about slow , but i bet other firefox user will not know that, and problem is also when did this happend, before it was show in the browser.