I found something weird - I recently posted a couple links in a post and one of them was replaced with entirely different text, but the link itself still works, and when I edit the post it looks normal (including the BBCode view):
Not only that, if I paste the link into the comment box and preview it the same thing happens:
Here is the URL in question, which does the same thing here as well:
That's really very strange; are you able to reproduce it following your steps when replying to this thread? I'm unable to reproduce it here. I would guess based on the fact that I can't reproduce it that perhaps it's an issue with an extension you have running in your browser, which could be ruled out by attempting to reproduce in incognito mode, however I'm not confidence that is the cause as I can't really work out what issue could manifest itself in this way.