are you referring to the 'messenges' column in the 'connections' tab?

i don't know exactly what is responsible for incoming outweighing outgoing or vice versa, but it think the following two are related to it.

i think ultrapeers, when talking to leaves, only pass stuff on that is relevant to the leaves, e.g. requests for files that the leaves actually share. since a leaf is not further connected (doesn't act as a hub), it makes no sense to forward messenges that are useless for these leaves.

a leaf sharing a bunch of files is likely to have more incoming than outgoing to its ultrapeers. the outgoing is merely you searches while the incoming is all the searches from the network that your ultrapeers forward to you. concequently, an ultrapeers should have more outgoing than incoming when talking to leaves.

hope that makes sense.