Duplicate MAC Address :)

Hi Forum,
I replaced my router yesterday, after having issues for months… albeit the new one is much better!
Anyway, I have an old CCTV unit, which has a very odd MAC (obviously failed in the factory) which is set to 00112233445566, this I know about. It is configured on my home network and does work fine… UNTIL my brother moved in with his MyCloud.
Essentially, I’d get the CCTV working on the new router, giving it an IP outside of the DHCP scope, and as soon as I plugged in the MyCloud, it grabs the same IP???

On getting a login to the cloud, it turns out that the MAC address on this is also the same! I know about the fact MAC’s “should” be unique, but for some reason my two devices share the same default MAC.

I’m thinking factory reset on the MyCloud?? The 40 second paperclip one? I’m hoping that the MAC has changed somehow, and a factory reset will put it back to as it should be.

Any thoughts??