ios - HomeKit characteristic value updated notification not called to remote device -

i have configuration: - iphone connected wifi network - appletv (3th generation) connected same wifi network - homekit accessory connected same wifi network - iphone b connected trough cellular

all devices (iphones , appletv) have same apple id logged in , wifi network has internet connection.

the issue we're facing changing characteristic value iphone iphone b not notified of update. changing value directly accessory iphone notified , not iphone b. changing value iphone b behavior correct (accessory , iphone receives update).

with iphone b if try write or read (readable, writable , supportseventnotification) property change correctly received accessory , iphone a.

why can't receive notification of change on remote device? should in particular allow notification process?