Oh. Thanks for noticing that.

I just changed gain GM=2, included these options (.opt cshunt=1f gshunt=1n itl4=100) and checked. It's still the same.

 

trouble with node " u1:_u3:50 " what that means is that u1 is the mcp6n11. u3:50 refers to the third circuit in the model file. And the 50 I don't know. Maybe you should contact microchip to confirm the model is accurate.