[imwjl]

Your home network can make more difference than is often realized, or than we care to admit.

Lots of insights come from my work and what we did at home. My work team supports around 40 who work from home, and the whole enterprise gives a lot of home support to hundreds of people. From that we often see the devices the ISPs give or rent are not so great, or people have home router/bridge/AP devices that are absolutely craptacular technology. Putting in the top devices, meshed WiFi, now more and more WiFi 6 has helped with some issues.

We have a lot of success suggesting or installing Ubiquiti Amplifi line for staff. That's a home office brand from a firm that makes enterprise grade stuff. The WiFi radios are good. Cisco Meraki is best but more expensive and requires ongoing licensing.

One way to test can be your cell phone. You can do the hotspot or screen sharing. Just personally I had a recent incident with our cable ISP where I showed devices worked better with the Verizon wireless network than their cable, and I proved the point was their cable modem, nothing we own.

It is a bit tedious, but for what I'm trying to explain, set up your item not working well as if your phone is the router.

Good luck.

P.S. The Amplifi and good gear let you speed test at the point of the ISP and eliminate what they might question as your problem. It did take reaching supervisors to believe that with our ongoing cable problems.
P.S.S. If the problem is your ISP and they don't fix it ask for a supervisor and in a nice way say you will be contacting your city's regulator or contact for the monopoly they've been granted.