I work for an ISP and we use the EP06-A in MikroTik routers as a failover solution. I bought a bunch of the EM06-A m.2 modules as the EP06-A has become hard to buy these days. Using the EP06-A 2x carrier aggregation works fine; it gets about 130 down and 30 up on B66/B12 (assuming decent RSRP). No matter what I do, the EM06-A will not do 2x carrier aggregation on towers where 2x carrier aggregation works fine with the EP06-A. I thought perhaps the driver for the EM06-A in RouterOS was the issue but I have the same problem on OpenWRT, Rooter, Debian, and Windows; no matter what I try, 2x CA does not work. I have reset the modems to factory which also did not help. Does anyone have links to the latest firmware image? I tried going through Quectel support and got nowhere after answering a ton of unnecessary sales questions.
Thanks for you query in Quectel forums.
It is suggested to try to replace the LTE SIM cards of other two operators for verification. you can also use a different carrier base station when using a SIM card from one carrier to another to avoid edge reception issues,Meanwhile, it is also suggested to test the MODULES in a better test environment of RSRP and SNR. I hope it will be helpful to you.