No worries Phil. I missed your explanation on the link function, yes it does say to insert the url by pasting it in the box when using the link function. Try writing out "Phil's video choice" in the post, now highlight that phrase and open the link function. Open another tab, find the video you want to play on youtube.com, let it start to play and then highlight the url in the address bar, then use a right click and copy the url. Come back to your post and paste the url into the link function box and hit the insert button. That should be it, ready to post.
Perhaps you do have some tweaked settings for using the forum? Not using tapatalk or something? Otherwise like the
Fleetwood Mac album, It's a Mystery to Me