When opening apps on Windows 11, even when only using a mouse, certain interactable elements are already highlighted as if I were navigating the UI solely via keyboard. The first notable example of this is within File Explorer. When launching, the title "Quick Access" which is collapsible is automatically highlighted in a tab-like way. Another is in Calculator, but with Calculator it's the field at the top which displays calculation stuff. (See screenshots for both examples).
As for what I've tried, searching about this issue it seems some others have had it. But responses are usually the same, "check accessibility/ease of access settings" and "this is actually a feature, not a bug" and things of that nature, which I have checked extensively and made sure what they mentioned was disabled (it already was) but nothing resolved this. I tried sfc /scannow, which didn't fix it. This is a relatively new installation of Windows 11 so I haven't really had the chance to trash up much of the default configuration yet, so I do feel a reinstall would be a bit much, and as far as I remember this has been happening since I first installed but don't recall this behavior in the previous times I've used Windows 11.