I just noticed something else which may be relevant. Depending on the context, the Youtube url that you copy may be https, secure http, rather than plain old http; the forum software does not recognize an https Youtube url and automagically convert it. Just remove the trailing 's' on such urls and it should work fine.
![[Image: extraordinarywoo-sig.jpg]](https://i.postimg.cc/zf86M5L7/extraordinarywoo-sig.jpg)