MAX-BR1-SLIM-LTE-US Not Failing Over to Redundant SIM in Slot B

I just purchase a MAX-BR1-SLIM-LTE-US-T and the WAN failover priorities work perfectly between WAN, WiFi-WAN, and Cellular in SIM Slot A. However, when I disable WAN and WiFi-WAN, for testing purposes, the Cellular WAN does not failover from SIM Slot A to SIM Slot B when I lose service from my provider (my Sprint connection seems to only last 4-5 minutes where I am currently located but I suspect that’s just a covergae area issue). Both of my SIM slots show that a SIM is detected. I currently have a Sprint SIM in A and a T-Mobile SIM in B. I have tried them reversed and still the same issue.

I’m currently running firmware version 6.2.2 build 1790 (which came on the router out of the box). I’ve also tried using the latest version, 6.3.1 build 2023 but that version will not recognize my Sprint SIM. Additionally, the only way I’ve been able to get the router to recognize my Sprint SIM in Slot A is to set the Network Selection to Manual and then scan and select Sprint. With T-Mobile in Slot A, I can leave the Network Selection set to Auto. I’ve tried setting SIM Card to B Only and then inserted both the Sprint and T-Mobile SIMs in the slot with neither being able to connect to the cellular provider.

Below are my current cellular settings. I have configured the email settings to warn me when I come close to reaching my monthly data cap (I’ve tried between 1-10MB) but I have yet to receive an email. However, I do receive them when the WAN status changes so I know my notification setup is correct.

Any ideas as to why SIM A is not failing over to B or why I am not getting the email messages when I reach 75% and 95% of my configured Monthly Allowance? Any and all help is appreciated.


Hi Rich

  1. Sim A not failover to Sim B when lost service on Sim A

Please elaborate more on the issue of “loss of service on Sim A”. You totally lost the cellular signal from the provider of Sim A? Fyi, Sim to Sim failover will happen when one of the Sim totally lost the cellular signal from the provider. If you facing service interruption (not cellular signal lost) frequently on SIM A, please enable WAN or Wifi WAN as priority 2.

  1. Auto Network Selection does not work in v6.3.1

Please open ticket for us to take closer look.

  1. E-mail notification does not send when Bandwidth Allowance reached

I suspect quota for Bandwidth Allowance was reached immediately once you enabled it with 1MB Monthly Allowance. Please do me favor below to do further testing.

  • Please configure “Start Day” as today date. For example 17 March.
  • Please check the daily usage of 17 March before configuring Monthly Allowance (Status > Daily > Daily Usage > Select WAN connection).
  • If daily usage is 0MB, you may configure to 10MB (for example). You can expect to receive e-mail notification after quota reached 75% and 95%. Else ensure the Monthly Allowance you configured greater than the existing bandwidth usage.

Email notification issue was resolved by changing the Start Date and Monthly Allowance values as suggested. Thank you.

In my configuration, my backhaul prioriities are set as follows to meet the operational needs of my customer when backhaul infrastructure is limited.
1- WAN
2- WiFi-WAN
3- Cellular

Loss of Service on SIM A-
With my Sprint SIM inserted in Slot A, my router connects to the Sprint network with the following signal levels-
RSSI: -86dBm
SNR: 6dB
RSRP: -110dBm

After 4-5 minutes, my cellular connection on SIM A drops and displays the following value and switches over to WiFi-WAN as I have temporarily set it as Priority 2 instead of switching over to SIM B-
Ec/Io: -2dB

I’m still currently running firmware version 6.2.2 build 1790.



It turns out one of the MAX-BR1-SLIM-LTE-US that I received is faulty and needs to be returned for RMA. Issues with the unit extended beyond just not failing over to SIM B. SIM Slot B does not work at all and some of the feature settings for firmware version 6.3.1 build 2023 do not appear in the web browser under the Connection Details for Cellular. I’ve listed some of the missing options below for reference-

Network Mode
Data Roaming


  1. Please help to take out the Sprint SIM in Slot A and insert into SIM B. Cellular WAN managed to connect to ISP?

  2. All the reported issue happen in this problem unit?

  3. Please help to open ticket for us to investigate on the missing features. It may not related to hardware problem.

Yes, all of the reported issues occurred in the same unit. My second unit works flawlessly and has been integrated into my system/network without any issues. The problem unit has been sent back for RMA and I should have a replacement by Saturday to begin building my second system/network.

Thanks for update :slight_smile: