So, my devices "stock firmware" supports VoLTE (android 6). Most of the ROMs that i have seen for my device (android 7.1 based) dosen't support VoLTE. After some digging in the internet, i found out that IMS is VoLTE and VoWIFI. So i copy-pasted the apks that have "IMS" in front of them ,from my stock firmware to custom rom, doubled-checked the permissions, and rebooted my phone. VoLTE didn't work. The secret code says "VoLTE Provisioned". Am i missing something? Or am i completely wrong about this thing? The manufacturer is samsung, if that helps in a way.