I think we are gonna go in circles with this @JerryJ
It seems the speed testers are fickle with how they provide results. If they were all 100% accurate and true there would no difference in results. But underlining factors play a role with how they each get those results.
Just be happy your streams are playing well. No need to measure speeds if all is going well.
I know which testers give me better results if i need my speed increased. Lol