1865688140 replied at 2021-02-12 21:18:32
Dear Xiaomi,

I just have a Mi Air Purifier 3H (global version) that has been successfully registered with Mi Home (Thailand region) and could control it via Mi Home straightaway. Unfortunately, it is extremely a serious issue that I could not link any device associated with my Mi Home account with Google Home/Assistant service to control the purifier. I receive a message advising that the service linked successfully but Mi Home does not display under linked services and no additional devices are shown in the Google Home. However, “Xiaomi Home” is just shown in Linked Accounts in associated the "Google Account Setting - Security" only. I am so much confident that the root cause is related to some technical problem on your Xiaomi system and/or Google side.

+1, I tried evething. It was linked and working. Suddently disappeared. And I am undable to link it again. Tried everithing: reset entrire networkk, factory reset router, facttory restet phone, tested on new phone, new network provider. None worked.

Tried to contact Google Home, same result.

I still hope that one day... it wil work again.
Thanks!