I had this happen to me last week. I had been looking for GPU-upgradeable flights the week before and ID'd some dates. I went back in to check and played around for awhile and had no problem. Then I got the same as you, no instruments listed on the upgrade list, even though I could see them on the top of the page. I logged back in. It did not get fixed. Since I wasn't going to book that day I just gave it up and added it to the list of website issues. You can still look for the W fares, book and then once ticketed go in and apply the GPUs via the reservation.

Today I went to log in and it doesn't recognize my MP number and PIN. I entered the security questions yesterday and that must have thrown something off. So now I can't even log in to my account. Their site is really a pain!