Your walls are going to be very difficult to get signal through. That’s why your outdoor lights are failing. You will probably need to have a repeater of the same protocol as the outdoor bulb near a clear glass window on the same side of the house.
If you want a bulb that will repeat the zigbee signal to the Sylvania device, assuming the Sylvania device is joined directly to the hub and not to your hue bridge, try an IKEA Tradfri bulb joined directly to the smartthings hub, not to the hue bridge.