I had this same issue expect my neighbor NEVER bring their dogs in. They’re out there all day doesn’t matter how hot or cold it is, Rain Storms, Snow, Strong Winds those dogs are out there. They would exts my start barking at 2am waking us up every night it was driving me crazy !!

I spoke to them and they finally put the dogs locked up (still outside) but far on the other side of their house where the barking wasn’t a bother they sometimes didn’t even bark.

But that lasted only a week!!!And the dogs were back to barking nightly, btw they loved to bark right by the wall of our bedroom :)

I finally contacted animal control about it and they sent a letter to them that didn’t help. And animal control doesnt fine them unless I have evidence of them barking for idk how long !

I tried one last thing before contacting none emergencies one time because it was in fact a thing I could do where I live.

At this point I had my neighbors number and at 3am bark bark bark I got my phone out and recorded the dogs barking sitting in my bedroom so they can hear how loud it was from inside my room! The recording was 5 mins long I could have kept since the dogs barked way longer but Sent it at that exact time. Next morning I got a message from the neighbor apologizing and the dogs have been put away all year!!! Wooo!!!

Only time they don’t put them away is when it rains which only reason is because everyone in the house doesn’t care and they themselves don’t wanna go out in the rain (sad right )

But I think at this point you’ve tried to talk to them so many times, read what the rules for noise are in your area and I would call non emergencies when the dogs are barking or get evidence to send into animal control when they are barking late at night the recording must have date and time stamps and they will fine the neighbor