Common mode choke in circuit with multiple ground connections
A choke increases inductance of the wires running through it. Currents take the path of lowest impedance when faced with two or more paths (the current actually take both paths but usually the impedance differ by several orders of magnitude with a choke or other inductor), so if a high frequency current 'see's the inductance from the choke and a low frequency path, most of the current will flow through the low frequency path. This will reduce the effectiveness of the choke. 







simulate this circuit &ndash; Schematic created using CircuitLab

If you need the blocking of the choke and its essential to your design, then you will need to move the ground so they both connect on the other side of the choke.