This issue has been tested only on iPadOS, (not macOS, iOS and other operating systems).

When connecting a mouse and a keyboard using a dongle or wirelessly, Minecraft will remove the joystick and buttons, which works as intended.

Pressing WASD, other keybinds, and moving the mouse will help you navigate your world, which also works as intended.

Pressing mouse buttons will make the joystick and buttons appear just like using touch input. After that, moving the mouse will only move the cursor, not the in-game camera anymore.

I can't confirm if this has always been there because I've just had an iPad. Windows and Android can play Bedrock Edition with both inputs seamlessly. Also, my set isn't a Magic Keyboard and a Magic Mouse, but a third-party set, so I'm not sure if these Apple products work well.

Product Model:

• Apple iPad mini 2021 - 64GB WiFi - Starlight.
• Apple Pencil Second Generation, AirPods Pro Second Generation USB Type C (irrelevant but has remarkable features for Minecraft, added because they may have compatibility issues)
• Dongle: JVJ C10 adaptor
• Mouse & Keyboard set: Wook ROBOT KM4000 2.4GHz