I don't remember all the details, but I've heard of this bug before. I was told you basically need to drop your quest for the trials and then wait a week for it to refresh.

Somehow they can get caught in a loop where every time all you get is the gold reward even if it has been a week. At least for maw it can.

Yup, it is extremely frustrating. I've missed two weekly trial rewards now, when my character wasn't put on the leader board with the rest of my group. The first time I didn't even realize what had happened. I just knew I didn't get my weekly reward mail on a character.

This last time another group member (there were five of us whose names were missing on the board) pointed it out to me, so I reported the bug. Never heard anything back. Then when the reward didn't come I submitted a ticket asking for my reward I didn't hear back from an actual person for five weeks and was told they couldn't help me. I asked if it could be escalated to someone else, and then after almost another week I was told in the future I should run the trial again if it happens and that they couldn't help me.