How to prevent custom launcher from being unloaded from memory?

Question

Java

Develops a custom launcher for Android. The problem is the following. Home screens consist of fragments on which applications are located. Let's say our launcher takes 40 MB of RAM. I open the resource monitor and open let's say Gmail. While I'm in gmail, I see how the place that our launcher occupies in the RAM gradually decreases until it is reset to 0! After that, I press the home button, and all our tabs reload. Is there a way to disable full unloading from RAM. I read that if the application is specified in the manifest as a launcher, then there should not be such a problem. But nevertheless it is. It is completely unloaded from memory while we are in it.