Have fastest Internet available in my area (up to 1200Mbps) - Cannot stream television and game at same time

So, according to the troubleshooting system, there is nothing wrong with my internet.  A speed test shows 668.4 Mbps on my laptop.

However, when we try to do game and do anything else (i.e., stream YouTube, stream, Netflix, talk on video call) at the same time, there are frequent lag spikes and disconnections (both on the game console) and on the other device).  We have tried all the troubleshooting steps and nothing works.   The automatic troubleshooting system says there is nothing wrong and we therefore are not allowed to setup a tech appointment (not my words, the automated systems says this).

Please, please help me figure out how we can do other stuff while the game console streams at the same time.  Heck!  We would really like to be able to have TWO consoles playing at once!