How to disable pop up window functionality on Sony Xperia 5 II

Got a new phone recently and noticed this incredibly annoying feature. Every notification in the notifications list has a little button on the right. It is very easy to accidentally click this button, which then opens the app in a small, draggable pop up window. I hate this window. I searched through android settings, and was able to find an option to toggle this setting off. However, when I did this, the buttons on the notifications still stayed, and when I clicked them by accident, I would get *another* notification prompting me to re-enable pop-up window functionality. I searched the apps list to disable notifications for this app, but could not find it. So I spun up adb, and searched the list of installed packages for "pop", "popup", or "window" and couldn't find anything. I want to know how to remove this annoying functionality from my phone.