Issue with remapping core binds on gambatte core

Description

Using PS4 (dualshock 4) controller on win10 retroarch with latest (as of today) gambatte core. Default binds have circle as the A button and cross as the B button. I have tried changing this so that square is B and cross is A. No matter what I change the controls to, the core will not register cross as A and will ignore if triangle or square are mapped to anything.

Expected behavior

The ability to remap any button to be any button on the virtual gameboy.

Actual behavior

Only default binding of circle as A and cross as B seems to work.

Steps to reproduce the bug

1. Install Gambatte Core
2. Try to change controls
3. Observe that they don't work in the game
4. May only be occurring with a DS4 controller. Works fine with x360 controller.

Bisect Results

Can't remember when I last updated the core, but a long time ago. Could be a very old bug.

Version/Commit

Retroarch 1.8.8.
Gambatte netlick v0.5.0

Environment information

• OS: Windows 10

Start by reproducing the remapping steps with a DualShock 4 on Windows 10 using the Gambatte core, comparing the behavior with an Xbox 360 controller. Trace the RetroArch input path into the Gambatte core; done means cross, square, and triangle can be mapped to the virtual Game Boy controls and work in-game.