OnePlus fixed that nasty bug that rebooted your OnePlus 5 when you called an emergency number, but just what caused it, exactly? The company has offered an explanation... and it's a thorny issue. Apparently, there was a cellular modem memory usage problem that kicked in when you made an emergency call while on a voice over LTE network, invoking the OTDOA (Observed Time Difference of Arrival) protocol used for positioning in an emergency. It only occurred on some OnePlus 5 units, but it was tricky enough that the company worked with Qualcomm to eliminate the glitch on devices around the world.