So I’m not sure if this is the problem affecting your friend, however, RCS messaging uses additional ports rather than just the standard tcp/443 port to send traffic. This port is specifically tcp/5223. If your friends connect to a wireless network that has a firewall that doesn’t have the port open, then the RCS messages will fail to send/receive until they are either connected to their cellular network or a wireless network that doesn’t have that port blocked.
The catch is, the RCS message doesn’t attempt to resend right away after changing to a network where the traffic is allowed.
I have a firewall in my house that has very strict rules and had to enable a policy to allow this traffic to be able to send / receive RCS messages when I was connected to my homes WiFi. My wife’s WIFi network has that port blocked so she doesn’t connect to it anymore.
If you want to see if this is the case for your friends connect, have them use their mobile network while sending / receiving RCS messages for testing.
So I’m not sure if this is the problem affecting your friend, however, RCS messaging uses additional ports rather than just the standard tcp/443 port to send traffic. This port is specifically tcp/5223. If your friends connect to a wireless network that has a firewall that doesn’t have the port open, then the RCS messages will fail to send/receive until they are either connected to their cellular network or a wireless network that doesn’t have that port blocked.
The catch is, the RCS message doesn’t attempt to resend right away after changing to a network where the traffic is allowed.
I have a firewall in my house that has very strict rules and had to enable a policy to allow this traffic to be able to send / receive RCS messages when I was connected to my homes WiFi. My wife’s WIFi network has that port blocked so she doesn’t connect to it anymore.
If you want to see if this is the case for your friends connect, have them use their mobile network while sending / receiving RCS messages for testing.