Have you tried without UBlock disabled? If disable and it works without issue vs when turned on it slows internet then the problem is UBlock and you need to contact their support. This is mostly for Firefox browser user help and issues with 3rd party software is to contact their devs about their software issues.

Thank you for your prompt reply. To answers some of your comments. I have already sent UBO support a message regarding this issue. It's been about two weeks with no reply. Also, When I ran FF is safe boot it seemed to run better. Also, I was thinking about trying Adguard to see if it made any difference. Last I have UBO installed on Edge and Chrome with no similar issues. Thanks and have a nice day.

Do you think doing a "refresh" help?

I first remove UBO and restart computer and disable all other Addon and then turn them on/off to verify those other are part of the issue as well then when you test each of them isn't the problem load them again and restart and see what happens again without UBO disabled.

Thank you for your reply. I disabled UBO and installed Adguard. Seems to run a little better but certainly not note worthy. I really think there is an underlying problem with FF itself. FF runs slow enough time it's annoying and downloading pages can be a problem getting hung up requiring I reload the page. I've done all the easy things e.g. disable little used extensions, cookies and cache are always clean and I even tried a safe boot. I'm thinking it maybe time for a "refresh". What do you think? At some point I'm going to stop using FF if this issue cannot be resolved. Thanks