@vashthest 

You could also try enabling NAT Boost (Advanced > System Tools > System Parameters), and disabling Access Control (Advanced > Security > Access Control).

If you still have slow speeds with multiple wireless devices then the Wi-Fi may be bad on the router which I would recommend contacting our support at that point.

@Tony Thanks for the suggestion! Appreciate it! I seem to have a very old version of the admin interface, so I don't have an advanced tab but the NAT Control Setting is Enabled and Access Control is Disabled and my speed is still pretty slow. I was able to get the 5GHz band to be 100Mbps after playing with more channels though, but my 2.4GHz is still at 20Mbps. Should I contact support?

Here's the navigation of my admin UI.

@vashthest 

In the older GUI, go to NAT, and make sure "Current Hardware NAT Status" is enabled. That option is your NAT Boost.

The environment you are at may be that your wireless speeds may not be what you may expect them to be. Adjusting the channels tries to move the router away from other channels causing interference slowing speeds. The 2.4GHz is a band that will give you range, but not speed. 

I would make sure to test with other wireless devices so the device itself is not the bottleneck. In the end I would contact support if speeds are not what you would like them to be.

@Tony Thanks for the message and advice. Super appreciate it. Nat status is enabled and the speed isn't changing. I ended up getting a UniFi AC Lite and will just use this router's wired connection.