Moto G5 Dual SIM - Why Can I Not Get Mobile Data to Work on My Mexican Telcel SIM Roaming on Rogers?

[noremac26]

Hi there.  I have just started using a Moto G5 dual SIM phone.  One SIM is Public Mobile and the other is Telcel, my carrier for when I'm in Mexico in the winters and which roams on Rogers when I'm back in Hamilton, Canada.  Data on Telcel is cheaper than on PM, even when roaming.  So, I have been trying to configure my phone to use mobile data on my Telcel/Rogers SIM and voice and SMS on my PM SIM.  However, it won't work.  When I configure as described, the Telcel SIM connects to Rogers in roaming, but my PM SIM will not connect to the PM network -- the signal icon is hollow, indicating no connection/service. 

If I configure the phone for my PM SIM to be used for mobile data, voice and SMS, then the PM SIM connects to the PM network, and the Telcel SIM still connects to Rogers in roaming.  However, this configuration does not allow me to save money by using Telcel for data.  It seems that PM is forcing me to use it for data.    Any thoughts on what is going on and what to try to fix it?  

[noremac26]

Yes, that makes sense, now I understand.  Thank you for the clear explanation.  

[sheytoon]

Is it possible one of the SIM slots only supports 2G?

Ahhh, @LEGO beat me to it!

[LEGO · Accepted solution]

@noremac26 If your sim slot 1 is set to 4G/3G, the other one will automatically be set to 2G. You can only use 1 sim for 4G/3G at a time. If you set your 2nd SIM to 4G/3G, the first slot will automatically be set to 2G. There is no 4G and 3G set on the phone at the same time either.

If you are using Tercel (SIM slot 1) for data, you cannot use PM (SIM slot 2), as Public Mobile does not support 2G frequency bands!

[MacMe]

Did you try switching SIM slots?