When using your device's call app, it relies on other installed packages to initiate, complete, and end a call.
When Lock Task mode is enabled, a side effect is that access to all packages or apps not explicitly listed in the policy is blocked. Therefore, it is necessary to include in the policy linked to the devices all the packages used during a call.
Below, we list the known components that should be allowed:
Common package for all devices:
com.android.providers.telephony com.android.phone com.android.server.telecom com.android.mtp com.android.contacts
Additional packages specific to Samsung devices:
com.sec.phone com.samsung.crane com.samsung.android.dialer com.samsung.android.incallui com.samsung.android.app.telephonyui com.samsung.android.mtp com.samsung.android.MtpApplication com.samsung.android.app.contacts