Your Orbi router or satellite is usually attempting to sync or connect to the network if you see a white pulsating light on it. But if the flashing continues for a long time, it's time to start troubleshooting.

Start by unplugging your Orbi system and waiting 30 seconds before plugging it back in. Verify that no obstacles are obstructing the wireless signal and that the router and satellites are positioned correctly within range.
You might need to perform a factory reset on the problematic device and go through the Orbi setup process once more using the mobile app or the web interface at orbilogin.com if the light is flashing white quickly. Stabilizing connectivity can also be achieved by looking for firmware updates. You can probably fix that annoying white light flashing problem and have full mesh WiFi coverage back in your house or place of business with a few simple actions. Remain calm and carefully identify the source of the issue and also read about Orbi Flashing White Light and many more.