I've said it before and I'll say it again: the diplomacy UI in FE just plain sucks.  It is almost completely useless.

Frogboy broke it even further when he introduced the new AI trade screen that offers absolutely no relevant information when an AI player offers a trade.

I always decline trade requests because I have no idea of what the impact will be if I were to accept.

From what I've seen, the pattern appears to be that the list of reasons is only set during the AI-turn processing and is not included in saves, like the list of city events or enemies in your territory.  When I first load from a save, the list of reasons is always empty; when I have ended at least one turn since loading, the list is always populated.

What he said.

Sincerely
~ Kongdej

At least it counts as a bump!
That said, I would repost this after the holidays, I think the development team is on vacation and isn't noticing any bug reports at the moment.

Sincerely
~ Kongdej