Can't get the correct skew for all transponders at the same time on one sat

[sewershark]

i live in Italy,i have a 125x135cm dish pointed to 7w, i receive with it with multi lnb configuration 30w ,signal for it is quite good 60-75%,the problem is no matter how accurately and slowly i skew or rotate my lnb when i receive the signal on some transponders IE: A B C D E i loose it on F G H I J K on 30w and when the receive it on F to K i loose it on A to E

is there a something that i am missing ?how can i fix this issue without buying another dish

Thanks

S.