So I think I figured out a workaround to make the iPhone 11 pro connect bluetooth and not drop the bluetooth connection.
Follow these steps:
1- Update you software to the latest release (Mine is 13.2.3)
2- Reset Network Connection (General --> Reset --> Reset Network Connections)
3- Put your phone on airplane mode
4- Restart your phone (hold power & volume up/down, then slide power off)
5- Wait 30 seconds
6- While you phone is off, turn off the bluetooth device you're trying to pair to (Forget connection on that device too if you can)
7- Restart your iPhone (hold power button until Apple logo appears)
8- Turn on Bluetooth on your iPhone (leave airplane mode "ON" for now)
9- "Forget" the bluetooth connection on your iPhone
10- Turn off airplane mode
11- Turn off WiFi (On the Wi-Fi tab in settings -- NOT on the slide down menu)
12- Re-pair your device to your iPhone via bluetooth
13- DO NOT turn on Wi-Fi (This will cause the phone to drop the bluetooth for some reason)
This will enable the bluetooth device to stay connected to your iPhone for now. As soon as it loses the connection, you will have to turn Airplane mode On again and repeat steps 9 thru 13.
I can't believe that Apple makes us go through this to use the bluetooth ... probably because they are trying to make the manufacturers of all these ancillary devices pay royalties!! When you pay $1200 for a phone that advertises bluetooth, it should work with ALL bluetooth devices!!
Hope it helps!!