From what I remember reading each individual rating is updated by using the overall rating of the opponent.
So if you play a 13x13 live game, your overall, overall 13x13, overall live and live 13x13 should all be updated using the opponents overall rank.
I think it’s relatively easy to understand why the overall rank differs from any one rank if you’re playing multiple settings, because the overall rank gets updated with all game information but the individuals only use a subset.
However if you only play one category exclusively, for example only 19x19 (maybe multiple time settings) or only live (maybe multiple board sizes) then you’d expect that that specific overall rating should be the same as the overall rating since they both use all the information because of the focus on a certain game type.
So I would expect 5 & 6 to be the same provided
which would cause the overall to deviate from the live.