Performance drop when playing LAN with another person

When playing minecraft with my brother we do connect with same wi-fi but that's not really important, when playing alone in singleplayer i can get around 60fps, but if my brother plays with me and connects to my minecraft world there is a certain drop of fps to 30 and causing lag spikes (the internet one, but i have good Internet so that's strange to me) my phone is Xiaomi redmi note 7