MBed Greentea testing framework resulting in SYNC_FAILED for all unit tests

Board: In-house designed/assemble board using the STM32F767ZIT6 microchip.

I’m facing similar issues with my custom STM32 NUCLEO Board. Pins are 1 to 1 compatible, so . I doubt its a hardware issue? I’m running my greentea on macOS 10.14.6. Thoughts?