Really incredible!
After been in contact with Xiaomi Support, they answered me to delete cache on a system app.
As my tablet is in spanish, the english of the support was really terrible and mine is less good than it should be.... I changed the system lenguaje to English in order to locate the app.
I could not find the app: all the options Support detailed were not present.
So, I do not delete cache in no one app.
But when I changed back tablets's lenguaje to Spanish... RR3 started working.
The problem dissapeared!
I am complete sure there has not been upgrade in Google Store's apps: I have disabled automatic upgrades of Google Store.
RR3 version is 12.3.1