How do I fix YouTube not working on Macbook Pro in any browser?

I have two Mac laptops, Macbook Air and Macbook Pro. I migrated to the Macbook Pro and I think I was loading YouTube fine at one point, but now, I can't access YouTube on any browser: Safari, Firefox, and Chrome. I've cleared the cache, restarted the computer multiple times, deleted then re-logged into the network and basically any fix I could find on google, but I still get error messages in each browser whenever I try to access YouTube. Safari says "can't access the server." Chrome and Firefox say: "not connected to the internet." But I can access other websites, Netflix, etc. with no issues, but with YouTube, nothing. In Safari, when I click on the website icon in the url window to select Website Settings, nothing loads when in YouTube, and the YouTube icon doesn't show up with the url at all like it does on my other laptop. It's like it can't read it or find it, or like it just can't connect to YouTube at all or doesn't recognize it, etc., but it works on my iPhone and other laptop work. And YouTube TV loads, just not the regular YouTube. I have two profiles on my Macbook Pro, both have the same problems with YouTube. I've gone through the settings for my computer several times, and for each browser and nothing changes no matter what I do. I'm at a total loss to fix this, please advise.

[Re-Titled by Moderator]

Original Title: YouTube not working on Macbook Pro on any browser and after clearing cache, etc. Not even showing up as connectable