Enabling of JOY SWAP feature from Freeze menu results in keyboard input failures in GO64 mode

[tonedef71]

Test Environment (required)

• Platform: MEGA65R6 (possibly earlier boards as well)
• Core Commit: 3c10488
• ROM Release: 920395 (and higher releases; possibly earlier releases as well)

Describe the bug
When the (J)OY SWAP feature is set to YES in the Freeze menu, keystrokes from the keyboard are corrupted in GO64 mode.

To Reproduce
Steps to reproduce the behavior:

1. From the MEGA65 BASIC65 screen, hold the RESTORE key to enter the Freeze menu.
2. Enable the (J)OY SWAP feature in the Freeze menu by pressing the J key until the setting is YES
3. Press the F3 to resume back to BASIC65.
4. Enter the command: GO64.
5. At the "ARE YOU SURE?" prompt, respond with Y and hit the RETURN key.
6. Press various keys on the keyboard and witness the mayhem.

Expected behavior
The key strokes in GO64 mode should not be compromised in any way when the JOY SWAP is enabled from the Freeze menu.

Screenshots
Screenshots should not be necessary.

Additional context
The impression given is that the key scanner is confused by other signals (e.g. phantom joystick readings).