I Know this is an old thread, but i wanted to share my experience of this issue.
I too suffered from dropped calls when using wifi calling, i do have between 1-2 bars of 4G inside the house but the signal drops intermittently and my outgoing audio drops out.
When using wifi calling, approximately 30% of my calls would get disconnected, i tried using different wifi access points to rule out the router and all had the same problem.
When i did eventually get through to EE tech support they could see the dropped calls and told me the reason was the phone constantly switching from wifi to 4G and back as the 4G signal changed in signal strength.
They advised me to use 'Airplane mode' and re-enable wifi to kill the 4G radio so it would not switch over, this is fine except you have to remember to switch off Airplane mode when you leave the house and on again when you come home, Not ideal!!.
Apparently, on older versions of Android (Android 11) there was an option to select 'prefer mobile network' or 'prefer Wi-Fi', which has been removed in later software updates.
However, this option is still available inside the operating system but no access to it from the UI, it can only be accessed by using the Android Debug Bridge (adb) software package installed on a PC (Win, Mac & Linux) and connecting the the phone by USB or WiFi.
This gives you access to the internal settings of android, the one which needs to be set is 'global wfc_ims_mode', this can be done by issuing the following in a terminal on the PC: "adb shell settings get global wfc_ims_mode" - to read (Default is null) and: "adb shell settings put global wfc_ims_mode 2" - to set,
This can be set to:
0: Wi-Fi only
1: prefer mobile network
2: prefer Wi-Fi
I initially set this to '2' but still had some dropped calls so i have now set this to '0'
This allows the phone to switch from WiFi to 4G only when the wifi signal is lost (when you go outside) and should switch back to WiFi when your phone gets back in wifi range, without the need to keep changing any settings (Airplane Mode)
You do have to be in 'Developer Mode' on the phone to perform the above changes, this was my solution to the problem and while i appreciate that not many people would even attempt to do this, it is not ideal from a user perspective and should not have to be done by people just to get access to a network feature.
The real solution would be to have the options in the UI to set the preferences you desire, this i believe is not the fault of the carriers, but down to the phone manufacturer and/or the android developers (Google)
This may or may not help but until we get the option back in the UI it is just one solution
Graham.
Telecomms Engineer (Retired)
