i'm going through something similar.
Current tenants have been there for about 3 years. new tenant moved in a few weeks ago right above them.
New tenant asked old tenants to please be quiet, that they talked very loudly. ( this was at 8:30AM on a sunday, new tenant had just moved in the previous day. )
all seemed to be okay.
Now i get a call from both tenants who are upset. Old tenants say new tenant was banging on the floor. new tenant says they were playing either the TV or audio books late into AM hours. ( 1:30-2AMish )
Next day, old tenant goes to talk to new tenant. both agree they were having a civil conversation, until old tenant's husband gets involved and goes berserk. tells new tenant he doesn't belong, leave.
new tenant closes the door and calls me the next day.
My side. Old tenant is kinda loud from time to time - during the day. I've heard them while working there, but during the day, i'm not going to say much of anything about it. At night, after 11PM. different story. Old tenants claim they were not playing the TV or anything in the morning hours.
so one big he said she said scenario.
talked with both tenants. remained fair to both sides. told them we can't have this fighting. no one is going to win. i also reminded them that if they can not have civil discussion, then don't have one at all. i will not tolerate yelling and screaming inside the common areas of the property. period.
that was two days ago.
hoping this issue goes away, because i don't feel like babysitting.