PaulTrubert Sadly, no. I haven't done attachments on this site. The difference in our experience is perplexing.
The only commonality between our experiences besides the end result seems to be a dependency on Javascript. There might be a clue in the Javascript that gets loaded with your reference URL
In your case, I'm guessing you have a registered SFR mail account and your login id and password are already saved by your instance of Orion RC. I wonder if the trigger has to do with the code that populates the login and password fields for you?

What if you go to Settings -> Passwords and disable the Password AutoFill options as an experiment?
John