5G Home Internet vs. phone data speeds

As these speeds go down when they say it is high congestion, is T-Mobile just pawning home internet customers to different isp servers for their phone customers to use their towers only? I wondered because I tested 2 phones with Ookla for internet speed over 100 times within an hour (10-11PM). On every test with both phones when WiFi was turned off and it was on 5G, all tests download speeds were between 180 to 251 and t-mobile phones connected to t-mobile Pittsburgh server (same server all tests show the Home Internet gateway connects to early morning around 350 until it slows down around 4pm around 100). But when tested on the phones with t-mobile home internet, same amount of tests for the "recommended best signal switching between 5G & 2.4G", -tests on 5G and tests on 2.4G during this same time as the cellular 180-251 5G tests, all scores ranged from 29 to 50 with almost all between 29-33. But the thing that I have a question about is because all tests were connected to different isp servers (Armstrong Cable in Zelienople, PA, Magna5 in Boyers PA or wVNET in Morgantown WV). From between 25 & 30 tests for each network, 100% of the T-mobile Home Internet WiFi tests connected to a non-t-mobile isp server far away from where I am located  and 100% of the 5G cellular network tests connected to the t-mobile Pittsburgh  network close to my home (that my TMHI is normally connected to except for evenings). Are they throttling TMHI customers or just pawning us off to other companies at certain times of the day?