With all do respect for your work, guys, I think it is. And I have discovered what's specific causes that issue. It's the John's winter holster that makes knife holster go crazy. Unfortunately, it can stay like that forever, even after removal of every single mod. I tried changing belts in wardrobe and with Rampage. No luck. Gladly, I had a savegame which wasn't played with mod, so that saved me a lot of trouble. But please check it out.
By the way - any chances to get J.M. saddle also as an add-on?