Wifi seems to segragate 2.4 and 5Ghz devices on M2 (MR2100)

[the_epoch]

The wifi on the Nighthawk M2 (MR2100) seems to separate the traffic on the 2.4Ghz and 5Ghz wifi bands.
A computer connected to the 5Ghz band can't print to a printer on the 2.4Ghz band. I have to change the computer to connect to the 2.4Ghz band.
If I connect to the router froom the computer on the 5Ghz band, I can see the printer's IP address connected on the 2.4Ghz WiFi on the router dashboard, but can't print or even ping it.
If I reconnect the computer to the 2.4Ghz Wifi print and ping are fine. I can't seem to find any setting in this router to separate the networks.      

#Nighthawk M2 MR2100

[rcpax]

Seems like your network have client isolation going on. but I don't see anywhere you would be able to set that for the MR2100. I would just probably factory reset it and reconfigure everything and see if that fixes it. when it powers up, leave the wifi settings to factory default initially and test client connectivity again and see if it fixes your issue. if it works, then you can customize your settings.

[the_epoch]

cheers for the reply @rcpax, unfortunately I've already tried resetting to factory but the same thing happens. And I can't see anywhere to configure this.  

[rcpax]

I guess worst case scenario you just disable 5GHz altogether and just use one band. Not ideal but if that solves the issue, I think that's the way to go. I would presume your wifi coverage area isn't that large for you to rely solely on the mobile hotspot for wifi, so 2.4 should provide you better range vs 5GHz, but your choice. I would assume you have tried updating to the latest FW?