Display fails to work if game starts on H32 mode and switches to H40 mode after

When testing a custom game that starts with H32 mode (8C70), then switches to H40 mode (8C81), all that is displayed is a black screen when H40 is active. This does not happen in the normal version of Genesis Plus GX, and the black screen issue doesn't happen when the game doesn't start with H32 mode. It also doesn't occur when the game's in H40 mode, switches to H32 mode, then switches back to H40 mode. Both of these have been tested with what's currently on RetroArch.

Wide version: https://github.com/user-attachments/assets/450f5802-04b4-4e23-9307-c854418d5066 Normal version: https://github.com/user-attachments/assets/dff448b8-9c9b-4bc9-a082-b98f15ac0fa7

ROM used: MD-SONIC RC2.zip