Why is the data dictionary incorrectly processed on Xiaomi in a push notification?

Question

Android

Hello!

I ran into a problem (which, thank God, did not have time to go into production) that Xiaomi correctly receives a push notification from the Firebase Messaging Service, the application service processes it correctly.
But the data card comes empty for the data dictionary:

remoteMessage.data

The problem is only noticed for Xiaomi.

Who faced and what you will advise for the decision?

Answer 1

UPD: the question is closed, because nothing was found on the open spaces of the network.
Decided to send body as a JSON object.