Trouble connecting multiple phones

[Andy_Liu(好想休假)]

It is kind of weird actually. I had JD controller on my phone which is installed few months before when playing on my friend's PS4 version. Today I decided to buy the PC version and want to play with my friends.
When connecting my phone and my friends' phones, mine will always work, connecting successfully while my friends who just download the JD controller app (both iOS and Android) can not work.
Any thoughts on solving this problem? Thx for any advices.

[laos159]

Check out if your friends' phones are connected to the same network (gateway) of your Modem, Router or AP.

[Andy_Liu(好想休假)]

thx for replying.
actually we are connected to the same network so the issue is pretty strange

[laos159]

Make sure if your friends' phones are not connected to a guest network.