The Philips Hue Iris lamp cannot be paired directly with the 1st or 2nd generation Philips Hue Bridge to be controlled synchronously with a round remote control if these older bridges do not support the newer protocols. The newer Philips Hue products, including the Iris lamp, are generally compatible with the 3rd generation Philips Hue Bridge or newer as these support the required protocols such as ZigBee 3.0 and Matter.

To ensure that the lamp can be controlled synchronously with other Philips Hue products, I recommend using an up-to-date Philips Hue Bridge that supports the latest protocols. This enables a stable and secure connection and full functionality of the smart lighting.