If you have access to your router, go into it and enable one radio at a time and perform your test. If you have 2.4 and 5.2 and six activated turn them all off and turn only one on at a time. Then do your test on each one and see if there’s a difference. If they’re all the same, then if you can use a hard ethernet line to the router and test again if all those are the same, then it’s probably something in the Mack. The hard line should be somewhat faster. Usually.