Need help with ZLT S20

[phybelongx]

I need help upgrading firmware of my Router ZLT S20 (Tozed Kangwei). I have TP-Link TL-MR6400 but it doesn’t recognize with my unlimited-sim card that came with ZLT Router. This is my third one and my previous ZLT S20 I can upgrade its firmware and use smart@home donut (chrome extension) to change its band frequency but the new one I couldn’t. My main issues with it is that I couldn’t change its band frequency to my preferred one, only have 2 options 38 and 41 and it’s very slow. Band frequency 1, 3 & 5 work best for my location.
Extra info for router.

• ZX297520 chipset
• Ram 64m + ROM 128M
  LTE : From 1 to 41 (But only 38 & 41 available)
  
  

[AndrewZ]

That has nothing to do with OpenWrt.

[psherman]

Please ask the manufacturer of the device or your cellular provider. This product is not supported by OpenWrt, so this is off-topic and the thread will be closed.