2019 16" Macbook Pro WiFI is unstable

You have remarkably high noise but good signal to noise 72-46 yields 26 good (not excellent despite high signal).

You are using channel 6 in the typically very busy and very interference prone 2.4GHz band. (Home to microwave ovens, baby monitors, and certain cordless [not cellular] telephone systems). The 2.4 GHz band is also used for Bluetooth, although Bluetooth does channel-hopping, that is still more potential data collisions and interference problems. You have several Bluetooth devices, and that competition is likely part of the problem.

You are achieving 144 M bits/sec (twice the baseband speed) by using two antennas. You have competition in this band from your personal Hotspot iPad acting as a Wi-Fi base station, and competing for Wi-Fi spectrum as well when used in this way.

So your network neighborhood is not overrun, but is busy. Your router should have moved you to the 5GHz band, if it had 5GHz band. Many company-issued Routers are 2.4GHz only -- they just issue those and wait for you to complain they don't work any more, then charge you more for a decent Router (that they should have issued originally) that has 5GHz band as well.

You can ADD your own Router to almost any modern Router by connecting it with an Ethernet cable. You do not need a needlessly complex and expensive 'mesh" Router.

Cable-Modem ------Cable-company Router ---- user-added Router(s).

.

Hello Gevanus and welcome to Apple Support Communities.

I see you are having some difficulty with Wi-Fi speed on a new MacBook Pro.

1) Start by doing a safe boot of the Mac. This will clear some cache files and give you a good foundation. After doing the safe boot, reboot normally and test.

How to use safe mode on your Mac

2) If the issue persists after a safe boot, set up a test user account in order to isolate the issue to the system or the user data and ultimately resolve it. 

How to test an issue in another user account on your Mac - Apple Support

Cheers.

there is this problem as well with newest USB-3 devices:

Why do I have difficulty with Wi-Fi or Bluetooth devices when USB 3 devices are attached to my computer?

Some USB 3 devices can generate radio frequency interference that can cause Wi-Fi and Bluetooth devices operating in the 2.4GHz band to have issues communicating with your computer. Here are some tips to avoid this issue:

• If your USB device has a cable long enough that you can move the device, place it away from your Mac—and make sure not to place it behind your Mac, or near the hinge of its display. The antennas for Wi-Fi and Bluetooth are located there, and USB 3 devices placed there might interfere with your wireless connections.

• If you're using adapters or dongles on a Mac computer with Thunderbolt 3 (USB-C) ports, plug them into the front port on the left side of your Mac, or into the ports on the right side (if your computer has them). These ports are the farthest away from the antennas, making interference less likely.

• To avoid interference on the 2.4GHz band using Wi-Fi, try using the 5GHz band instead. You can change this on your wireless base station. Bluetooth always uses 2.4GHz, so this alternative isn't available for Bluetooth.

from:

<Apple article no longer available as written>

Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support

.

Most Wi-Fi problems reported here are not caused by anything inside your Mac. They are most often used by really old Routers or really crowded network neighborhoods (or both).There are a few other things that show up less often.

Hold down Option as you click on the Wi-Fi Icon on the menubar. Screenshot or transcribe the snapshot that appears, with the parameters below.

Also, How many Networks do you see?

.

You don't need to turn OFF the provider's Router's Wi-Fi. You can use both and "Roam" (walk about the house, switching back and forth automatically) if you give both the same Network-name and password. Just set your new Router to BRIDGE rather than ROUTE new connections, so that it does not pass out addresses via DHCP, but merely acts as a wireless Access Point.

So I suggest you think about putting a new Router distant from the existing one, but accessible via Ethernet cable. For Ethernet connectors, Leviton makes a wall plate that has keystone (push-on) wiring to a jack on the back the wall plate, so you can run "bulk" cable and cut off and terminate in a wall-box. Then make the last 6 feet by plugging in a standard Ethernet cable.

On your iPad:

Settings:

• Airplane Mode

• Wi-Fi

• Bluetotth

• Cellualr

• Personal Hotspot --- turn OFF when not needed

• Notifications

• Sounds and haptics

...