Max Speed GL Slate?

So I’m a novice and I just got the GL Slate today. I’ve tried several scenarios to try to get much better speeds. I’ve tried wired connections between my att netgear nighthawk where I got I think 37 mbps. Ive tried other examples but I can’t remember exactly what they were but it involved usb tethering etc. my best speeds came with using a sprint hotspot via usb where I got speeds of about 60 mbps. I know the theoretical speeds of this devices is 300 0n 2.4 and 433 on 5g but I’m trying to get at least 150 to 200 please. Can someone help me?

Same problem. They won’t help, they’ll say it’s normal.

I tried everything, I couldn’t pass 70 mbps at 5ghz