Well for me its the same thing if i run one masternode or two.
When i had one this command gave me the same error.
Now i have two and its still "This is not a masternode (code -1)" message when i type "masternode status".
When i start them it says successful for both. I can see them working with masternode list, its just this command gives me that error.
Yeah, I'm getting the same error now as well. Not sure what the problem is there, was working before. I'll remove it from the guide for the time being.
I
think it's because you're running your MNs on VPS. With that command you're checking the status on your local wallet instead of your wallets in the VPS.
It's a small thing since it's not necessary for the start up and there are other ways to check to see that your MNs are enabled.