I’ve used the Minicube several times now, and while not the greatest quality in build, I have not yet had trouble like you describe. At this point, I can only offer some debugging suggestions.
Check your signal wires between ESC and FC, the 6-pin cable that attaches to the connectors on each board. Besides the ground wire, there’s an unused power wire position, and then four signal wires, one per motor. Try swapping those pins to verify that it’s a problem with ESC 3 as opposed to a bad wire.
I’m unfamiliar with “m4wFCIntf”, which seems like the interface you chose in BLHeliSuite. I’ve used the Cleanflight interface. I have no idea yet the significance of those interfaces, but that looks different than I’ve done in the past.
Check your power, ensuring it’s as you expect and sufficient. I’ve had issues lately with ESCs acting erratically when I didn’t provide enough voltage. Also, when I received the Minicube, it had an LC filter, which I later learned was only a noise filter, not a voltage regulator. Can you tell more of what battery you are using, and give an image of your connections including ESC + FC + battery?
I don’t think it matters, but if you’re using USB “passthrough” (I think that’s how it’s referred to), where you connect to the ESCs by connecting the FC to USB, and then program through the 6-pin connector between the FC and ESC… try to downgrade the protocol that is selected in Betaflight to Oneshot42 or maybe even PWM.
Just some thoughts, hope those offer some things to poke at.