We had the same issue as well. After multiple testings with few guild members, we found only very short messages are being sent (like one or two words), rests are just disappeared in the middle of transit. No error message, nothing. If there are attachment it remains in your inventory.
I had similar issue, but in my case, promised promo items appeared under [PROMO] tab in [Reward Claim Agent NPC] So make sure to check Both NPCs. Items appeared around 2:50 PM PST on 22nd
Probably a side-topic, but to me it sounds like you haven't had a chance to play other support classes beside MoF CW. Before making a generalized claim, please take a careful look on what other support classes do first in game. As a good example, if you look at classes such as DC, you will find most of encounters will…