Depending on how you copy and paste the link, the board doesn't always like it.
From what I can tell, if you click on the down arrow, select 'Copy Link' and do a regular paste, it doesn't like that for some reason. If you do the same but right-click and do a 'Paste as Plain Text' it will work. Or you can right click on the timestamp in the tweet and select 'Copy link address' and paste that here and it will work.