Hi again Yaya
I know I told you to try an earlier bedtime, but if your findinf that he's playing and cooing in his crib till 8 there are 2 options.
1) persist with 7pm bedtime and leave him be. Thats of course when he's just playing, is happy, but just isn't sleeping.
2) Move bedtime. For your LO 7 may in fact be to early. Try maybe 7:30 and see if maybe that makes a difference
Some LO can stay up later then others.
As long as your LO is content you don't have a lot to worry about. Your doing a really great job, you'll find his bedtime