You are supposed to be able to stream while an event is being recorded, but something to look at incase you have the same issue I do. I use the TPLink Deco x60 Mesh system with a gigabit up and down.
I actually have a ticket opened with Wyze now. Here is my thread:
I have a Camera in the backyard which does not seem to have an issue but need to verify this tomorrow. In front I have 2 Camera’s and a doorbell. When all of them are triggered, streaming has issues.
So I am trying different options at this time. Clearing the Cache seems to worn more for me. But I am getting closer to a potential solution or narrowing what the issue is.
I have also set a higher priority to the Wyze Cams on my network. I thought this would provide more bandwidth to the camera’s and therefore resolve this issue. Not yet. 
I am planning on doing more exhaustive testing this weekend.