Why does sound go silent when opening and closing mixer?

Been using Cubase for a very long time and this never used to be an issue but it is now. I have no idea what setting may fix this but once I start listening to my recording the sound will go silent for a couple of seconds every time I minimize or maximize the mixer. Is there a way to fix this?

Also, when I just came to this site while listening to the recording it went silent. When I leave this site and maximize cubase it picks up playing where it left off. If anyone knows what’s going on that would be great!