Bluetooth disconnect when entering Wifi after mobile data connection

[dideldum]

Hi,
I have a glucose sensor connected via Bluetooth to my Mi 9 SE (MIUI 12.5.1 global, Android 11 RKQ1.200826.002). This glucose sensor sends the glucose data every minute via Bluetooth to an app. This works stable, whenever the Mi is connected to a known Wifi (even with 2.4GHz) or when it switches to a mobile data connection.
But whenever it switches back from the mobile data connection to a Wifi (when I come from the garden back into the house, for example), the Bluetooth connection to the sensor is lost and I don't get the glucose values anymore. This behaviour is reproducable. Wifi/Bluetooth: works. Switching to Mobile Data / Bluetooth: works. Switching back to Wifi/Bluetooth: Bluetooth connection lost.
In this moment I can set the phone to flight mode and back to normal mode, and Bluetooth connection to the sensor is established again. It is NOT enough, just to turn off Bluetooth and turn it on again, the connection is established only after a flight mode switch.
I use the Mi 9 SE for years now, and this behaviour is happening for a few months now. I suspect, it started with the last firmware update, because this behaviour wasn't there in the years before.
Is there anything I can try to configure with Wifi/Bluetooth (in the developer options?) to get the stable behaviour, which I had before?

 

[Igor Eisberg]

Hi, I placed this Post in the bugs forum, but it was now moved to the Q&A forum with the comment: "nothing to do with our ROM".
As I wrote, the described wrong behaviour has happened probably since the last firmware update, so it is very probable, that it HAS to do with the ROM, as I use the Mi 9 SE for years and the wrong behaviour didn't happen before. So I see definitely the reason in a ROM bug since the last version.

Your post was moved because you clearly said that you're using "MIUI 12.5.1 global".
We are not Xiaomi Global, so you clearly don't know where you are.

https://c.mi.com/forum.php

Good luck.