I have a new credit card and went to https://chaseonline.chase.com, completed the account signup and saved to 1P. When I went to login, the user name was something completely different (IIRC 3601), not the text name that I had created.
Thanks for reporting this issue, @GIGAmacro.
The Chase websites do quite a few unique and special things that have caused their share of filling issues over the years. We spent a great deal of time recently making sure 1Password supported all the Chase login pages, including this one. I just tested this on my Mac using the latest beta versions and I was able to save and fill the signin form correctly.
If you're on Mac or Windows you can switch over the betas and try for yourself. Or if betas aren't you're thing, no worry as these should be released relatively soon.