2 old ipads to mac connection problem

(i hope i can ask this question here)

my problem is
i have 1 ipad 3rd gen (A1416)
i wanted to use touchosc (overmidi not osc)
and chord poly pad to my mac (ableton)
so that that old ipad doesnt support multitask and that i wanted to have my old ipad dedicated only for touchosc i bought an cheap ipad same model.
on 1 ipad i have only touchosc not over the bridge (it doesnt feel stable) but over midimux
on the 2nd ipad same
chordpolypad over midimux

but in ableton its weird sometimes booth works great than at some point one ipad disconnects
to reconnect to the mac i need to restart the ipad
the other ipad with the touchosc is on some point really slow or doesnt respond immidatly
or on the first ableton project everthing works great
when i start a new one
1 ipad disconnects and the other gets not responsive like touching touchosc cmnds and bleton reacts few seconds later :frowning:

is there some issue with multiple old ipads with mac using them only on midi mode ?
i tryed also to use multiple connections like midimttr and midimux ?
is it maybe an usb power issue ? booth ipads are sticked into usb-3 ports.
whats really annoying is that at some point the 2nd ipad disconnects completly from the mac and i had to restart the ipad

hope that somehow it could work so i didnt fail buy that 2nd old ipad XD.

booth ipads modell A1416 3rd gen ios 9.3.5