LTSpicie - op amp wrong output

Further info about AC gain in LTspice, if interested:
The simulator initially calculates the circuit's voltage/current bias design values.
This is then used to determine the AC (small-signal) gain value for all the active devices.
From those gain values, the total circuit gain for an AC signal is calculated.
Since this AC gain value ignores the actual changes due to any non-linear characteristics of active devices, the gain calculation is thus unaffected by signal amplitude.