That's call the sleeping transition for most babies. I had a sleepless night for my second born for first few weeks she's home. Subsequently she get up once a night. Now, she's at 3 months old, before her bedtime she will have a lot of short naps or she will not sleep till 10pm/11pm. It is not that we do not practice early sleeping time. She does have her daily routine, in fact better than my first born. My first born wakes up every 3 hrs last time when she's a baby. It is so tiring.
To me, we just have to let them adapt to their style subsequently change it whenever we think it is right. We can't force them to sleep if they can't even despite giving FM before bedtime to make them full.
itsallabout_mytwokids