farpras

Happening on latest 1.21.50 update as well. I'm on Win11 23H2.

Can confirm this happening on my Arch Linux GNOME 47 Wayland session. No cursor issue on X11/Xorg.

EDIT (Nov/2): It seems the issue is more related to Gnome and KDE with Wayland rather than Minecraft. I tried playing on Hyprland (Wayland compositor), and there was no cursor issue.

The MCBE icon in start screen app list is fixed in Windows 10 20H2 because in this version of Windows 10 app icon has no background anymore, but it's still has this problem when pinned on taskbar.

So I think the black border is actually a background that added automatically by Windows because the MCBE icon is not made in the correct size.
And I think what the dev need to do is fix the app icon size❓ .

Docs of app icons & logos for UWP apps:
https://docs.microsoft.com/en-us/windows/uwp/design/style/app-icons-and-logos 

you mean the difference between MC Bedrock and Java icon?

they already don't look the same either way. (top: Java, bottom: Bedrock)