I've had this problem since forever. It didn't just suddenly occur one day, I mean it's always happened and I haven't addressed it yet. Until now. So whenever I use the 'Youtube' tags in any post it doesn't work. I'll give an example in this very post Using This Link Here:

Here I've used the long link. I'll try the same video but using the short link you get when youtube gives you the 'Shareable Link':


At first I thought this was a browser issue. So I checked for updates of my current browser (Google Chrome) and I have the latest version. So then I tried switching to Microsoft Edge and it made no difference. But what's even more strange is that if the video I try is part of a Play List, it actually SOMETIMES works. I'll give an example using the same video but just the one in the playlist:

In this case it didn't work but finding the same video just in a youtube play list has done in the past. But this is still a MAJOR issue for numerous reasons - not every video is in a playlist.