TP-Link is aware of the problem that customers’ Alexa/Google stops working with Kasa app in some cases.
Alexa/Google can't control Kasa devices via voice command. It worked before and suddenly stops working. When the problem occurs, customers can still control Kasa devices remotely using the Kasa app.
Updated on Mar 25, 2019
The issues with Alexa and Google have been solved. If problems persist, unlink the TP-Link skill in the respective app, and relink it.