Help activation required and battery loss

Hello,

I'm traveling and have arrived in a foreign country. Each morning after charging my IPhone 6 to 100% battery and leaving it to sit overnight, I wake up to find it at 43% or so battery and with a notification saying "activation required" that requires me to put in my Apple ID and password in order to use my iPhone. I thought this might have something to do with Find my IPhone as that was mentioned at the bottom of the activation required screen but my cousins who have iphones and find my iPhone have not had to "activate" theirs. My cellular data and roaming are off.

THanks for any ideas and help you can offer!