Volume down button will not work, unable to restore

I have a rose gold iPhone 7, A1778, unsure of any other specs, and it needs to be reset as it is currently disabled. The volume down button doesn’t work, so i am unable to enter recovery or DFU mode. It also has “unlock iPhone to use accessories” so it’s not recognized by my pc. When i replaced the button flex cable, it still did not work. Put a different board into its housing, and all the buttons work fine. i couldn’t see anything wrong with the connector or any damage to the board, or find anything online. is there any other way to force it into recovery mode, or does anyone know what the issue may be? the phone is in very good condition, almost brand new, and the battery is at 100% health, 180 charge cycles. The screen is shattered right on the earpiece/front camera.