Ahh ok cool, good to know..
If it helps, on the previous issue that the user above me posted, I've also encountered that diplomacy trade issue as well, but only so far with the America Faction in this game. (This is the same game where I'm Morocco)
I tried to trade for 2 Iron and they wanted my Lapis Lazuli and 7 Gold per turn, and 30 Gold, accepted, but the trade wouldn't go through.
Than I went to Carthage in that same game, and asked for 1 iron, they only wanted Wine and for them to Accept their Embassy, accepted that, and that trade went through without problems. All of us are in the medieval era.
I already have an existing deal with America for Horses perhaps that had something to do with a possible bug? or could it be a conflict with the added Luxury where the game is not recognizing that new luxury?
I always clear my cache before I use a new version of your mod (didn't clear the mod user data folder this time, not sure if that causes issues though..)..
If you need me to link any files, just let me know what directory I should be able to find it, not as savvy when it comes to find those files you need, as I normally just play and not really report any bugs, but defiantly enjoy your mod a lot so want to make sure I can contribute in a tiny way if there's issues to help you improve it
Edit 1:
Just tried trading that same Lapis Lazuli to the Celts in my game instead just for 4 gold per turn and that went through without issues.. So it seems to be centered around the American Faction with that specific item. I'm gonna see if another opportunity of trading something else to the American Faction works (technically it worked earlier cause I do have an existing deal with them)