Sleep training

My LO is 9 months she was really good with sleeping but once she turned 7 month her sleep schedule change and I’ve been trying to get her back to her old schedule she was wake up at 8 go back to sleep at 10 wake up 2 sleep at 5 wake up at 7 go to sleep at 10 or 11 and not wake up til 8 again now she sleep at like 12am wakes up at 2 am not sleep until 5 am then wakes up at 2 pm and I try to keep her up or get her to sleep at the old time but she won’t she’ll still wake up in the middle of the night