Hmm , do not know if it helps this info but who knows?
First , i do not know the structure of grimarrilion , i just play it and also the version i have is not the latest , also the version of the game that i have is 60 .
In my case it was different because i created a mod and addedthe caravaner into it ,do not know if it will work for other mods but this is what i did and the issues i had :
- Downloaded caravan/inventory Mod .
- Opened the file and from there i added/copied from records>ui the character and caravan folders in my ui folder .
- Also i added/copied the caravaner folder located in Sources to my sorces folder .
- Runned Asset Manager and created assets for the files located in sources>caravaner.
- Build and i thought it was done .
Entered the game and i had the same problem you had , at first i did not wanted to add the game engine from the Caravan Mod because i already had my own and i did not wanted to modify again the rewards and other stuff.
Saw that it looked fine but it had the same space , so i thought why not try to change the game engine ?
I did that and it worked , also important to delete the caravaner arc in mods before building the mod .
Had to modify again the engine but the problem was solved .
Changing the game engine solved my problem, try to see if it works in your case.