You can't increase streaming speeds this is based on ISP speeds regardless of the browser. The Browser doesn't control internet speed that is done by ISP and what bandwidth speeds you subscribed to. Also ISP speeds aren't Streaming speeds. The two are not equal one is to your ISP and the other is to the streaming service and where it comes from. And those streaming could be affected by a mirad of other factors beyond the ISP control.

What is need to know is how was was your firefox update or upgraded? Sometimes doing this to FF57+ causes firefox corruption.

thks, yes we can rule out ISP speed as the problem since Chrome works well using same ISP service. To update from earlier FF I just followed the standard dowload proc to get to current v66.0.2. If not the browser then perhaps its a media player prob at my end. Somewhere within FF info I found that prob might be video player related so i attempted to load Win Media Feature Pack as suggested but got msg "not appropriate for my computer" (presumable because I already had media player loaded. If not browser and not media player prob, any other possible fixes?

So what is the streaming site your using? If others use that site they can verify the problem with chrome and firefox for problems. ISP service isn't the same as Streaming speeds let's separate the two here.