Is this the 6 month regression?

Baby was sleep trained and woke once a night for a bottle. Now he’s waking up at 12 am, 2 am, he won’t go back to sleep unless I give him a bottle (which he doesn’t even finish) and wakes up every day at around 5:20 babbling, which turns into crying. I tried checkins but the crying got louder and it was crazy to go through with that. First night it happened he reached 30 mins which had never ever happened before. So I rock him until he gets sleepy and sleeps. (I know big no no but at 5:20 I’m pretty sure sleep pressure is super low). Then he sleeps till his usual wake up time : 7 am.

Wake windows: 2/ 2.5/ 2.5/ 3

He falls asleep on his own (with a bit of crying still) and the wake ups before 12 am usually last a minute then he goes back to sleep. (These didn’t happen before either).

Is this a regression or am I doing something wrong?

Thank you