Ok. So on that vehicle, the power is supplied by FETs. The LH and RH side lights have their own separate FETs, so if one side isn't working, it's either the FET has gone into current limiting mode, or has failed.
If a FET is in current limiting mode, you can try a hard reset, which means disconnecting the battery for 30 minutes or so. If you're lucky, the problem will go away. If not, then a diagnostic read will be needed to identify the issue.
The side light ground is shared with the indicator and main beam bulbs in the headlamp unit, so if those are unaffected, the ground is OK.