Mobile Push notifications stop when Discord open on PC?

I use discord bots for very time sensitive information and often without realizing that discord is open on my PC, I no longer receive notifications on my Phone anymore.

Why is that? All other apps in existence work simultaneously ? Whether it's e-mail, whatsapp, social media apps, even games.

can you please address this, I can see from the search results, this has been an on-going issue for years!!