Both of these scenarios are actually incorrect. You are trying to use both as DNS in an incorrect way.
Indeed.
If you set your nameservers at GoDaddy to be the Digital Ocean nameservers then you need to manually copy the entries from MiaB’s External DNS page. You do not redelegate with a NS record there. Using a NS record would only be if you have a subdomain’s whose DNS is being hosted elsewhere. Something incredibly complex, and unneeded for 99.999% of people using MiaB.
I misunderstood how GoDaddy glue records work when I initially set up my box. Once I went through and followed the instructions correctly, everything worked as it should.
This actually makes no sense for there is no setting to ‘set up the external nameservers in your MiaB admin’.
I was referring to this, whatever it is:
If you set your nameservers at GoDaddy to be the Digital Ocean nameservers then you need to manually copy the entries from MiaB’s External DNS page.
This is in fact what I had done previously. It… mostly worked. It was just needlessly complex.
Yes, this is true, but why are you wanting to delegate other subdomains to DO ? Why not have MiaB handle it all? Granted, like I mentioned earlier there are rare cases in which you may want to do this… but if that is the case here, you did not do it the correct way.
I have a handful of other DigitalOcean droplets on other subdomains. (For example, I have a full Nextcloud setup.) Having the DNS in the same place as those seemed more convenient at the time, and I was actually already set up on DigitalOcean before I started using Mail-in-a-Box. (I had previously used a weird MX application that used DNS records for everything. It didn’t work very well, which is why I switched to Mail-in-a-Box.)