Hello RRMS-Toronto,
Welcome to the community!
Are there any options to select APNs for each SIM? From the list of APNs you provided, the APN for Telus is missing. It's likely the information is hardwired on the Telus SIM itself. When the Telus SIM is selected as preferred, the phone is able to access the information. However, for some reason, the phone is not able to access the information when the Fido SIM is preferred. Most dual-SIM phones should have the option to select APNs for each SIM.
If there is no option to select an APN for each SIM, you might consider adding the Telus APN on your phone. Simply having the APN in your phone may be sufficient for the non-preferred SIM to access the information.
Hope this helps 
Cheers
No worries! You did really good!
Try this: can you select the Fido SIM card as preferred data, and then select the APN that has LTEMOBILE.APN.
Then go back in your settings --> Wireless & Networks --> Cellular networks --> Preferred network type and make sure that you've select a connection mode that has LTE active.
Let me know if that makes any difference.
Hello again,
If we backtrack a little... Where did you get your phone? Are you sure the phone has compatible bands/frequencies? I haven't been able to acertain reliable specifications for that phone (not even from Acer). DeviceSpecifications suggests that phone has 3 compatible LTE bands/frequencies and only one compatible '3G' band/frequency. However, SpecOut suggests the phone has both '3G' bands/frequencies and only one compatible LTE band/frequency. You can verify the compatible bands/frequencies here.
@RRMS-Toronto wrote:
...
I followed your instruction however, only have a 4G option in network type. Same as lteactive?...
Some phones might denote a LTE connection as 4G. On the other hand, some phones required some additional tweaking (see here) for LTE. You might consider contacting Acer to determine whether 4G=LTE.
**edit**
@RRMS-Toronto wrote:
...
Just noted that switching to other sim causes Perferred Network Type of deselected sim to become 2G.
...
**
Are you sure the non-preferred SIM has full 2G, '3G', and LTE access? **edit** Many dual-SIM phones do not offer full capabilities for the second SIM.** For example, the Asus Zenfone 2's second slot is only 2G-capable. That would be consistent with your finding that the deselected SIM shows as 2G. If true, then it explains why you get no connection or network error when the Telus SIM is set as non-preferred. Telus does not have a 2G network.
Hope this helps
Cheers
@RRMS-Toronto wrote:
...So the question remains with me is why? I have selected preferred net type as 3G but it changes back to 2G on its own. Is the problem with SIM programming or is the Android software to blame assuming I have a 2G connection available?..
Hello again,
As far as I am aware, the Acer Z630 is a Dual-SIM-Dual-Standby type of dual-SIM. While both slots might be capable of 2G, '3G', or LTE individually, this type of dual-SIM device can only do '3G' (or above) on a single slot. The other one always gets limited to 2G.
The 2G or GSM limitation on the second slot is because both slots connect to the same set of radios. You can option either slot to run up to LTE, but when both are in use only one slot will receive data. The other slot will be limited to GSM since the radio can't simultaneously have two open LTE/3G channels. This is a hardware limitation.
Dual-SIM-Dual-Active phones can have both slots operating at '3G' or above because they have two sets of radios. Those types of dual-SIMs also require greater processor power to be able to support two high-speed data connections simultaneously.
That said, is there an option to disable data on the non-preferred SIM-slot? The restriction to GSM is because it is generally the network for voice and SMS. However, many providers do not operate GSM networks anymore. It's possible that with data disabled, the phone may recognise the UMTS(WCDMA) network for voice and SMS and allow the connection.
Unfortunately, if the phone does not accept UMTS(WCDMA) for voice/SMS, I cannot envision a scenario where both those SIMs can operate simultaneously on that phone. If the Fido SIM is preferred, there will be no access to the Telus SIM because Telus does not have a GSM network. On the other hand, if the Telus SIM is preferred, the Fido SIM would not have access to your 3Gb of data.
Hope this helps
Cheers
Cawtau wrote:...That said, is there an option to disable data on the non-preferred SIM-slot? The restriction to GSM is because it is generally the network for voice and SMS. However, many providers do not operate GSM networks anymore. It's possible that with data disabled, the phone may recognise the UMTS(WCDMA) network for voice and SMS and allow the connection.
...
Hello again,
Alternatively, is there an option to disable GSM on the phone? I understand you set the preference to 3G, however, that does not preclude switching to 2G.
My phone has the option to select UMTS(WCDMA) only for its network mode. Perhaps a similar option on your phone could indicate the 3G network is to be used for voice and SMS.
Just a thought...
Hope this helps
Cheers
