Meeting forward notification enabled does not work

Question

Hi Team,

I Created a meeting invite with an internal recipient and had them forward to another internal user. Result: The organizer received a forwarded notification as expected

case2: Sent a test meeting invite from an external mailbox to a internal recipient and then had the recipient forward to another internal user. Result: the original external sender (organizer) did not receive a forwarded notification

could you please let me know forwarded notifications are only triggered for internal meetings within the environment??