baby keeps waking up screaming

can someone give me advice? my 9mo keeps waking up crying and crying as soon as i put him down. it just started the last few nights and this was happening a few weeks ago too. he wouldn’t go to bed until 1:30am last night and I had him asleep but i would put him down then he would just wake up crying after a few minutes. idk what else to do i haven’t changed his bedtime routine.