I can confirm that adding a custom link does clear all of the links in discourse_narrative_bot.new_user_narrative.onebox.instructions. The surrounding < > are not shouldn’t be the issue as they are simply to ensure the link is displayed ‘as is’ and not oneboxed.
I’m afraid I do not know whether this is expected or not as yet. But in the meantime I suggest resetting the field and using the existing ones. 
Okay, scrap that answer. I think I know what’s happening. 
The < > that ensure the links stay as text and aren’t oneboxed are making the sanitizer think they’re some HTML code that’s not allowed to be in there and is cleaning them up on save.
But if you hyperlink the address in markdown instead then this seems to work as you want it to. eg
[https://meta.discourse.org](https://meta.discourse.org)
Update: Using a regular <a href="https://meta.discourse.org">https://[test.site](http://meta.discourse.org)</a> style link also seems to work
Could you give that a try while we look into it further?