First, Save near a NPC who has this problem
Disable your mods, then enable them one by one, always checking in between whether or not the problem persists. Once the problem reappears, you know you've activated the problem mod.
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A secret message to the chosen ones:- Spoiler:
011010000111010001110100011100000111001100111010001011110010111101110111011101110111011100101
110011110010110111101110101011101000111010101100010011001010010111001100011011011110110110100
101111011101110110000101110100011000110110100000111111011101100011110101100100010100010111011
10011010001110111001110010101011101100111010110000110001101010001