AD8131 Single Ended to Differential Problem
\$25°C, V_S = ±5 V, V_{OCM} = 0 V, G = 2, R_{L, dm} = 200 Ω\$

Input  Common-Mode  Voltage = −1.0 to +4.0 V

Output Voltage Swing Maximum ΔV OUT ; single-ended output 1.0 to 3.7 V

These are the specs.  Read carefully.