After the Android 11 / OneUI 3.0 update, I noticed overly aggressive RAM management. Before apps will hold in memory without reloading. Now it seems like anything beyond 5 apps will be booted out of memory pretty early. Also, it deletes it from the Recent Apps list which is even more annoying. I remember this was an issue either when the s20 first released, or back during a S10 release or update that Samsung has to fix. Please fix this soon Samsung!
Edit: Almost forgot to mention, when u reboot, the apps the were deleted from the Recent Apps list reappear back in the list. I already deleted OneUi data, but that didn't prevent apps from disappearing from the Recent Apps list.
Hopefully they fix it soon. But since the S21 will be here next month or two, I'm not overly angry, just annoyed for the time being. This has been an issue in previous phones and has been fixed eventually.