@BlueFlame17 

Hi,

Do you have any other wireless devices that you could use to do a speedtest of this wireless network from the same location? (for comparison)

How far is the T3U Plus away from the T-Mobile router when you get 20 to 95 Mbps?

I've just tested an Archer T4U under Windows 7 plugged into a USB 2.0 port and got about 250 Mbps data throughput when I am close by the router.

  @woozle My distance from the router, Approx 25Ft.  But antenna/ routers is poorly set up.  Owners responce, it fine for me, it must be you. He doesn't do speed tests...

My only other divice is Moto G Stylus 2021:

Ookla SpeedTest = 52Mbps (today) App.

Speed of me = 35 Mbps (today) Web based.

Google speed test = 31 Mbps (today) Web based.

The software thinks the routers up/down link is 433 Mbps.

Bruce

  @BlueFlame17 

If the router is only capable of providing a link speed of 433 Mbps, then that's already a disadvantage.

And unfortunately, the strength and quality of Wi-Fi signals drops off quite rapidly as the distance is increased or obstacles get in the way.

When moving around within your own premises, can you find a spot where the reception and speed improve? 
Sometimes it can make quite a difference when the distance is a little shorter or there's just a door instead of a wall. Years ago I was in a similar situation and I ended up connecting my USB Wi-Fi dongle via a long USB extension cable to get a better connection.

  @woozle My issue is, that if the serving device, said it can provide 433 and I realy get 10% of that at 43Mbps, this seems slow to me.  However, I typicly get ~20-30Mbps, which is half that.  I'm not really compaing becouse 25Mbps is plenty fast enough.  But thats no were near the expected amount...

  @BlueFlame17 

If you are concerned your particular T3U Plus might have a hardware issue, then perform a speed test with it while it is very close to the router. At about 2 meter (6 feet?) distance and no obstacles in between a Wi-Fi connection that is rated at 433 Mbps link speed should be able to reach around 250 Mbps actual real-world speed, provided the 5 GHz channels in use are not occupied by traffic of neighboring Wi-Fi routers. (so it would be best to test at a time when people are usually not at home or when everyone is sleeping)

  @woozle 

Around 3AM Sunday, I got 90-110Mbps. Where normaly 50Mbps is the best I've ever seen. And 25 is more typical.

  @BlueFlame17 

What is the type of broadband connection used by that T-Mobile router? Is it some sort of fixed line or via cellular signal?

I am now wondering whether you may be on a 4G connection and the speed numbers you are seeing is basically whatever that 4G connection can manage at various times of the day?