Maybe someone can offer some advice.

I believe the bug is in the Characters/Heroes/Dungeon/Kaldoin/Raelag_LOD.(Character).xdb file.

If the paths to the models are incorrectly specified in it, the result will be exactly as described.

So, why isn't there a bug with Kaldoin in Heroes? The path to this folder is the same for both Kaldoin and Cordar.

Added after 59 seconds
And even if you take a standard model from the original game, the same thing happens, although there shouldn't be any errors in the Characters file.