Water coming out waste port when pumpnis on filter

We had a broken later line and replaced it. After replacing lateral line assembly water started coming out of the waste valve once the pump was turned on.  We checked everything and couldn’t find any problems, so we ended up just purchasing the whole top multi port valve.  The water is still coming out, and I don’t know what else there is to replace?  I am starting to think the lateral line assembly pipe is the wrong size?  I purchased one for a 19’ and that is what my tank is marked as?

Thank you for contacting Inyo. What is the make and model of the filter? What is the diameter of the tank?