Slow Wired and Wilreless Internet speeds on my HP Spectre x360 laptop

[MSTEGER]

I have 2 HP laptops.. one is an HP Spectre x360 (model 13-4003dx) running WIN10 x64 (all available OS updates are installed). All drivers appear to be the latest versions, too. The 2nd laptop is an HP Envy (also running WIN10 x64) and all OS and drivers are updated. The Envy is my wife's laptop.

I subscribe to Xfinity's Boost service (300 Mbps). When running Ookla's Speedtest app on both machines, I get considerably different results.

On the Envy running in wireless mode, Ookla measures  b/w 300 Mbps and 400 Mbps from a few different nearby servers. I've run the test repeatedly with similar results.

On the HP Spectre, I get about 100~125 Mbps in wireless mode (5 GHz band) with the laptop within 10' of the cable modem/router (Motorola MT7711). In wired mode (using an Insignia Ethernet to 3.0 USB adapter), I get about 140~180 Mbps) using a cat 5e cable. I've tried different cables with similar results.

I had a Comcast tech here a few weeks ago and he also measured 300+ Mbps on his test device (wirelessly using 5 GHz).

I get similar results on my iPad and iPhone (11 Pro)... 300+ Mbps using 5 GHz using the Ookla Speedtest iOS app and using the same local servers on my iPad and iPhone.

I have no ethernet card in the HP laptops (as HP doesn't supply them anymore) so I am limited to either the wired connection using an Ethernet to USB 3.0 adapter OR the laptop's built-in wireless card (2.4 GHz and 5 GHz). Changing wire channels make no change in the wireless speeds and I have channels set where there is little to no other signal. I also ran BIOS' own USB port check and everything checks out on all 3 USB ports.

Can anyone suggest what else to try and what may be the cause(s)?? I use the wired (ethernet) connection most often in my office so why are the wired and wireless connection speeds so low on my HP Spectre x360 compared to my Envy and my iOS devices?  Are there settings somewhere (in WIN such as in the registry) limiting my internet speeds? 

I know wireless speeds will vary depending upon the environment and if other items are in the area using the 2.4 GHz and/or 5 GHz freqs but I am doing the tests on the Envy and Spectre in identical conditions.. especially the wired connection is the most troublesome to me. 

Thanks.