I know working with the iPad over wifi is not an 'official' midi controller solution recommended by Serato. But I have seen many tuto on youtube of people who managed to set it up.
I have a few bugs myself :

1/ some buttons that are inactive:
push "PLAY" button, push button "enable/disable" the effects (the strenght button for effect works but not the ON/OFF), push "mute" for sampler sounds.
The strange thing is that I have tried and it worked for one session and not anymore.
I have tried using TOGGLES instead of PUSH, but it doesnt do.
Would you have any tip to give me?

2/ buttons that create a bug:

the push "OUT" of in & out looping that automatically goes back to the begining of the track.
The 'K' symbol of an arorw going backward supposed to get back to the begining of the track when I click it in the keyboard, is different on the ipad: it goes directly to the previous track!

3/ Reassign button when serato is quited and re opened.
I have some other bugs where I need to reassign buttons ( loop roll sometimes, and the IN of the looping)

thanx very much!!