I ran into the bug mentioned in this thread. I was able to change my reservation on one ticket, including applying travel funds, and then I couldn't do it on another ticket, so I did the workaround where I canceled it and then rebooked. However, I ran into another bug, where if you try to apply 2 travel funds, and one has an earlier expiration than the other, no matter what order you enter them in, the website will always apply the full amount of the "fresher" travel funds, rather than the "older" travel funds. I didn't have a problem applying the full value of the "older" travel funds first and then the "fresher" travel funds on the old website.