Strange issues with wifi connection on a pi 5

Im a first time pi owner, and I've run into an issue that I'd like to solve properly. When I first started playing around with pi os, Ubuntu, plasma, chrome, I ran into an issue where I could connect to my home wifi network, but get horrendous (30 to 78 B/s up and down), or no connectivity to the internet. No browser will connect to any site.

The pi os that came preloaded on a micro sd was hung up on some update that wouldn't go through. I decided to try a fresh rewrite of pi os , which was able to fully update without issue, and the internet connectivity issue vanished.

But has returned. Interestingly, using my phone as a tethered USB hub yields the same strangled up and down performance.

Does anyone have some ideas of how to identify what's allowing me to connect to my wifi network, or a tethered connection, while barely flickering in terms of upload and download speed?