Poor Upload Speeds on MacBook Pro 2023 with M2 Max chip

From the parameters shown, in this location, your raw signal, at -76 db is FAR too low, and you are in imminent danger of disconnecting due to complete loss of signal.

These numbers rend to vary from about -40, right next to the Router, to as low as your -76, which is simply unacceptable low for reliable operation.

Signal-levels falls off as the cube of the distance between Router and computer, so 'how far away' is very important. Also, Building materials that intervene can attenuate the signal. Solid masonry can severely reduce the signal.

So a quick check is to carry your Mac next to the Router, and look at the RSSI number there (remember these may be a little slow to update). In addition to FAR better transmit rate, you should see use of TWO antennas (NSS=2) when the signal improves.

What should it be?

When setting up offices with multi-Router coverage, the advice is to provide at least -65 dB at every location in the building.

if your provider is using cable-TV cable as the input medium, your modem/Router can be moved to ANY point on the connected cable -- it does not need to remain in the basement where the wiring enters the building.

The Signal Strength (RSSI) is very low. The Signal Strength should be somewhere between -30db and -60db (even at -60db you may start to experience some issues....I know by -63db I had issues). The Noise level is actually Ok.

Is the laptop Clamshell open or closed? I have seen people report weak signals when using the laptop with the Clamshell closed.

Try the laptop at different locations relative to your WiFi access point/router. Best case is trying it with line of site to the access point/router, but sometimes being too close can cause problems too.

Try power cycling the router or access point to see if that makes any difference.

You can also try checking the Signal level & speeds by testing the laptop on another network. If the issue occurs only on your network, then you know the laptop is Ok. If the issue also occurs on a different network, then the problem is with the laptop. Either way you know where to focus your attention.

Are you running any system intense tasks? I have seen macOS report incorrect WiFi information when the system is working hard or is sluggish in general.