Trans leak up front

Having the same issue but more of a drip. No puddle. Here's the thing, the trans 904 is now acting when I drive it hard. Having a 1-2 f!are up at times and occasionally have to back off throttle going into 3rd. Shifts OK when I drive it normally. Level is OK. Not sure of mileage but I've put about 12k on it. Figure it needs a refresh but will do a band adjust first. I guess my question is, Does a front seal leak cause this perhaps due to some pressure loss?