It’s nearly impossible to sleep train while they are changing their sleep pattern, I’ve done everything I knew with both my 4 year old and 4 month old. They have their own clock. I will say switching to baby food and a warm bath at night has helped keep her asleep once she’s down. But that’s after a few hours of her wanting to party lol.
Here for comments because I also have a fresh fourth month old boy - who just seems to be fighting sleep at every corner ! Also not a fan of crying it out sis so I get ya. I was also suggested the gradually dial back but increase the feedings in the day time to aid in alertness so ultimately he’ll begin sleeping longer by night fall
We attempted sleep training but once the sleep regression hit, we decided to wait until that passes to resume sleep training. Our Ped told us you can sleep train during a sleep regression but it’s very taxing and that sometimes for your own sanity it’s better to let it pass before trying again. This sleep regression is their brain trying to hard wire the different sleep cycles so their brain doesn’t want to sleep much anyways because of this. I have found that white noise machines help to keep them asleep during the sleep cycle transitions