Internal bluetooth on raspberry pi 4

I have the internal bluetooth setup on my raspberry pi 4 and am eventually wanting to have it work with XIAOMI Mijia Bluetooth Thermometer 2 Wireless Smart Electric Digital Hygrometer Thermometer, but have not purchased them yet.

What I am trying to figure out is what kind of range to expect with the the internal bluetooth adapter since I have it in the basement and am wanting it to reach our 2nd floor? Then if it isn’t strong enough, is it recommend ded to get a USB bluetooth adapter with an external antenna to meet my requirements for coverage?

When trying to do some testing with getting the internal bluetooth of the pi 4 to connect to my phone on the first floor, they see each other but when they try to pair, it just fails. This was my method for trying to see the signal stremgth of it but can’t see what it is.

Curious if you have anything plugged into USB like a zwave/zigbee stick? I am having the same issue and think it might be my Zwave adapter is using the ttyAMA0 path?

hi
I just bought 2 Xiaomi thermometer
miaomiaoce.sensor_ht.t2
and in my case using a Xiaomi gateway v3
lumi.gateway.mgl03.
The gateway is in the bedroom 1st floor, and the first sensor in the ground floor.
The other sensor is to far away to gateway but close to the Raspberry pi 3 so I would like to use raspy Bluetooth to connect the sensor
can anybody tell me if it is possible?