"In certain situations, a bug in the Cast software on Android phones may incorrectly send a large amount of network traffic which can slow down or temporarily impact Wi-Fi networks," wrote Google. "The specific impact to the network will vary depending on the router."
As per our previous reporting, customers with ASUS, Linksys, Netgear, TP-Link, and Synology wireless routers were experiencing the performance-related problems -- that list alone covers some of the best-selling wireless routers on the market. TP-Link, which gave a thorough analysis of the problem before Google's patch was posted wrote this:
This issue stems from these devices' 'Cast' feature, which sends MDNS multicast discovery packets in order to keep a live connection with Google products such as Google Home. These packets normally sent in a 20-second interval. However, we have discovered that the devices will sometimes broadcast a large amount of these packets at a very high speed in a short amount of time... This issue may eventually cause some of router’s primary features to shut down—including wireless connectivity.
Google says that the Wi-Fi connectivity problems were most pronounced for those with an Android smartphone that is connected to the same Wi-Fi network as a Chromecast or Google Home device.
The fix was pushed out to affected devices via Google Play services starting yesterday. In the meantime, Google is imploring customers to reboot their Android smartphones and ensure that their wireless router has the most recent firmware installed.