Noisy neighbours

I guess this is more a vent than anything else. We live in a semi-detached and our neighbours have always been generally pleasant. They are a retired couple but have several grandchildren who range from newborns to about 8. They’ve always been super loud but we’ve never took too much notice. We have a dog who can sometimes bark to be let in or out and it’s always been part and parcel of having a semi. They had never head our son in the night due to us co-sleeping initially but at 7 months we transferred him to him own room which is right next to their bedroom. We did warn them there would be crying etc and they assured us it was fine and they didn’t mind. Fast forward to now where we’re pretty sure they are pissed off at the night crying as they have started to do things they never did previously for example hoovering their bedroom or hammering flat pack in their room at 8pm/9pm. Also their grandchildren have been playing in their bedroom and they are all (including adults) screaming at the top of their lungs. They have also started playing what I can only assume is a piano. I like to think I’m not a “Karen” I can literally make out conversations it’s no longer muffled anymore. The frustrating thing is the worst my boys day naps are the worst his night time sleep is and vice versa so if it is intentional they are doing themselves no favours! Not sure how to even go about it because I feel like I can’t really say anything.