Background noise on a amplifier even when no audio is playing
A starting point to troubleshoot an apparent 'BUZZ' with a shorted input would be to power your audio widget separately with a low-noise supply (like a linear bench lab supply).

If you don't have a supply handy, you can excessively filter the incoming power rail. The no-load but active quiescent current of the TPA6111A2 is 3 mA. So you can easily add a series resistor of 100 ohms and afford drop 300 mV. Add additional bypass capacitors to lower the low-pass filter even further.

Layout is also critical for performance, tie the ground leg of Ci as close to the op-amp ground pin as possible.