what would you do with this situation?

he is not sttn yet- im okay with that though as i know its still early plus he does seem to be getting himself on a schedule of a routine having his last bottle around 8 and then falling asleep, however when he wakes up during the night hungry, he drinks only half of the bottle and falls asleep.

i cant wake him slightly by simply talking to him, turning the bottle or touching he cheeks, etc. the only method for waking him up is to fully wake him by turning on the ceiling light or changing him (even when not necessary). then he will wake and finish the bottle but then will take a long time to go back to sleep.

so the only alternative, it to let him fall back to sleep, but then, since he only had half of the bottle, give or take, he will wake up 2 hours later (still in the middle of the night). and then the same scenario might happen again. SO, here i am again back to square one like when he was 1-2 weeks old with hardly any sleep, waking up every 2 hours.

Btw, I tried keeping him up past 8pm and giving him another bottle around 11 or so, so that he would stay full longer. BUT, this didnt work- he wouldn't wake up or take a bottle. I also tried not giving him a bottle at 8 so that he wouldnt fall asleep and be hungry later on, again, staying full longer but I cant seem to get him past 8 without eating and then sleeping.