@ado Try to disable the 5 GHz band when configuring the Chromecast 2 device. After successfully connecting the Chromecast device, the 5 GHz band can be activated again.

I had problems connecting Chromecast 2 with my TP-Link Deco M5 system. After some trials I found out that if disable the 5 GHz band when doing the configuration in the Google Home App then it was...