It depends on multiple factors why a domain is not considered as an exit link. There can be two scenarios when your internal domain is redirected to external link. One is open a popup and second is change the internal URL to external on the same page.
To handle both of the above scenarios, make sure you perform the below steps:
If you use both linkInternalFilters and linkExternalFilters simultaneously, the clicked link must match linkExternalFilters and NOT match linkInternalFilters to be considered an exit link. As there is no explicit outbound link defined in Launch, please uncheck "Track Outbound Link" option
If this does not help, then help us with the URL and steps to reproduce or raise a case with client care team to troubleshoot further.