After more research, I’m suspecting that the reason I can’t link to exploitzeroday.com is because I’ve already linked to that domain enough in previous posts. In that case it’s a spam prevention measure, but you should probably whitelist a few domains.
Trying again, now that I’ve reached “Basic User” privilege level:
https://exploitzeroday.com/system/7/
Edit: That worked! So the bug report then is, “Whitelist a few domains for all user types to get past spam prevention methodology.”