Echo Dot vs the Microwave.

My Echo Dot speakers are interrupted by my microwave when playing music as a group but not when playing in a stereo pair for TV. Any idea why?

I double checked to be sure the Echos are connected to the wifi at 5GHz and not 2.4GHz. 3 of the 4 are very close to the router, but so is the microwave. The 1 furthest away from both the router and the oven continues to play just fine. Just really curious what is different when using the Echos as a Stereo Pair?