I had 2 MacBook Pros. One 2024 and one 2019. The 2024 one would connect fine to the internet, the 2019 one would not.

After pasting in the airportd logs of both (into ChatGPT and Gemini) it found it was down to band switching (2.4GHz and 5GHz) through some really old error code.

This fixed a problem that had plagued me for >12 months. Really magical feeling it got in on first try.