Wi-Fi Slow on One Computer, But Fine When Tethered to Cell

[cupler2]

OK, I have a funky issue. I have 150/150 mbps service, and my laptop is running about 4/112 on Wi-Fi. I checked every other device in my house, and they are all running normal speeds, so I assumed my network card may be dying (my laptop is Wi-Fi only, no Ethernet port).

I decided to tether my laptop to my cell to double-check before blaming the wireless card, and bam: 40 mbps through my tethered cell phone. So it is definitely not my card. Any ideas?

I run a 1-year-old Dell 15.6-inch touchscreen laptop with Windows 10.

Thanks!

 

[anotherdrew]

I knew someone who had a failing antenna ... as long as you were extremely close the WiFi source (hotspot), then service was ok. Over any reasonable distance, the service was crap. The only weird thing your download is crap, but upload is great. Maybe the adapter uses 2 antennas?