https://wccftech.com/google-home-chromecasts-found-disrupt-wifi-networks/

Google products have had their history of disrupting WiFi connections, with the first reported device being the relatively unknown Nexus Player. The gadget reportedly flooded the network with hundreds of gigabits of data, causing it to crash. Now, according to user reports on various forums such as Reddit, the Google Chromecast and Google Home speakers are creating a similar disturbance in wireless networks. In some cases the router is inaccessible for a while, other users report the router only temporary disconnects from the internet.

Initially, the problem was thought to be linked to a specific router brand (the problem was first reported by multiple people using TP-Link routers). However, later on, several non-TP-Link users also reported the same issue. The issue has been confirmed for routers from Asus, Linksys, Netgear, TP-Link or Synology. TP-Link and Linksys have acknowledged the issue.