Sptiz GL-X750 with EP06-A getting error when chcking CA, please help

I just purchased the Spitz GL-X750 with the EP06-A modem as a backup and travel router and wanted to find out why this router has consistently lower connection speeds then my other router with MC7455 modem. Then I noticed when I issue the AT+QCAINFO the EP06-A response with ERROR. Is this modem not provisioned for CA?

Shouldn’t this modem be able to achieve same download speeds as the MC7455?

This is tested with a T-Mobile unlimited and unthrottled data plan. I also added in the custom firewall rules a TTL=65 setting so that TMO doesn’t throttle due to tethering issue.

We have many tests with EP06-A and MC7455 and they achieve almost same speed.

EP06-A should do CA automatically. This may broke if you have ever lock band. In the latest firmware you can use AT command to set the band to default.

There is also an AT command to reset the modem to factory default.
AT+QPRTPARA=3

You can also change the module to MC7455 and the firmware support this module out of box.