Steps to reproduce:
1st method:

1. Switch to the D-Pad & tap to interact control mode
2. Create/enter a world
3. Place down and ride a boat (with chest)
4. Go to Settings -> Touch and enable Customize Controls (Experimental)
5. Go to Customize controls
6. Press Done
7. After resuming the game exit the boat by pressing the Leave Boat button
8. Attempt to move your camera around with 1 finger

2nd method:

1. Switch to the D-Pad & tap to interact control mode
2. Create/enter a world
3. Place down and ride a boat (with chest)
4. Open and close your inventory
5. Exit the boat by pressing the Leave Boat button
6. Attempt to move your camera around with 1 finger

Observed result:
You can't move your camera around with 1 finger until you interact with the screen with 2 fingers.

Expected result:
You can move your camera around with 1 finger normally.