Car in Drive when Press on Gas takes a while to drive forward on 2000 Subaru Outback

When I put car in Drive, and then take foot off break to press on gas it delay's going. After a period of time it does drive but won't take off initially. Just replaced transmission fluid with 1 qt.

Asked by for the 2000 Subaru Outback
The transmission should not loose fluid, it must have a leak. It sounds like a transmission problem that will require transmission removal but have it checked out first and have someone with a scan tool with Subaru diagnostic capabilities see if there are any stored trouble codes.