This seems to be fixed in a scenario where no other conversations are open. Here is the message we get:
“Close confirmation request – Closing a conversation window automatically ends your call”
However, the message changes to “You have multiple conversations open. – Do you want to close all conversations?” In an scenario where user got chat and active calls. Call will end when confirming this warning with okay.
The message should be more specific and alert the user that call will end if he continues.