Problem roaming in Vietnam

[wes345]

I just arrived in Vietnam and have two sim cards in my iPhone.  My eSim is able to connect to local vietnam cell networks with no difficulty.  But my Three sim card only connected to the local cell network in the area around the airport.  The Three sim is not connecting to local networks outside the larger city.  There is definitely cell service since my eSim (not a Three sim) is connecting but the Three sim is not.  Can anyone help sort this out?

[PeteG]

Hello, Wes. 

It's strange that it connected in some areas but not outside of those areas. What is the connection status showing as? Is there any error messages or notifications that relate to network or roaming? 

Pete.

[wes345]

Hi, thanks for your reply.  There are no error messages.  No bars at all for the Three Sim.  The eSim has four strong bars and is connecting fine to the various networks in the area.  We have two phones, each has an eSim and a Three sim and neither phone is connecting to a cell network on the Three Sim line.  We will soon be spending more time in a larger area so hopefully we will have service on the Three Sim line, but this is annoying. 

[Maxine]

Just to double check, has your international roaming been activated on the Three SIM?

Maxine

[wes345]

Hello - yes, international roaming is turned on.

[jr0]

for the Tree sim, check if the "preferred network type" is restricted to 5G only or 4G only or 3Gonly