@iansari version1.6 is probably the same as v1 device so the software is the same, and this is a all in one device, so you have to wait for a updated firmware from tp-link to get 5.9. thats the only...

@iansari You have the latest update to this device. Firmware download is on this location. https://www.tp-link.com/no/support/download/er7212pc/#Firmware

@yorkman

@yorkman this is new not long ago, the devices to be upgraded must have access to this port on the controller, so you need to check that you can reach the controller from the network the devices are...

@Mr.Blue that was very strange, that device should easily handle 300Mbps, this seems to be a case for tp-link support it seems like there is something that slowed down the speed somewhere.

@Mr.Blue What speed have you on LAN interface?