Alright well i somewhat figured it out. Didn't think for a second i could save during the customization, that at least allowed to work arround.
right, so i'll be honest it might just be the usual crashes that happen with all those games on mobile. Except this one was just more severe and would seem to really like to happen during population customization. I've lost my phone, now i got a new one that has much better performances so i'll see if the crash issue is as severe.