I know this problem has been going on for a while but all the fixes that I found (not that many) were not effective for me.
I own a Mi Box 4 and recently (a little bit less than a month ago) the Google Assistant on my phone and on my Google Home mini just stopped working with it. I would request to do anything such as turn up the volume or cast a certain song from Spotify and it would always say something along the lines of "something seems to have gone wrong. When you're ready give it another try".
I've tried factory resetting my Mi Box, deleting the Google Cast Receiver updates and reupdating, deleting my Google account, using airplane mode + manually turning on Wi-Fi, deleting and reinstalling the Google Assistant app, deleting and reinstalling the Google Home app and even factory resetting my Google home mini. So far none of these helped.
Are there any other solutions or fixes which I can try except for waiting for a software update which won't solve it because it's a multi platform problem (meaning I've seen this problem on almost all android TV boxes and Built-In Chromecasts) which Google needs to solve with their own software update? I would really love to get a solution as this problem has been so frustrating throughout the last few weeks.
P.S. -
Images will be inserted bellow.
P.P.S. -
I can change the volume manually from the Google home app perfectly fine and I can cast from all cast enabled apps directly but not through the Google Home app nor from the Google Assistant
Images:
Can't play songs from Spotify: http://imgur.com/a/QlEANy3
Can't communicate with Android TV: http://imgur.com/a/sNj5oRe