When I ran this, 1) I am not used to "spinning up a web server", never had to do it. 2) It created the cert with Let's Encrypt instead of Digicert. How do I make it use Digicert (this is pretty much the command line their help system says to use)? It worked with Digicert back last Fall ok.
This is a forum to help get and use Let's Encrypt certs. Your question is about using Certbot for Digicert so would be best addressed to Digicert or even the github for Certbot.
Then you probably didn't use the standalone plugin previously, maybe the webroot plugin? "Spinning up a webserver" is just one of the few plugins possible with Certbot to validate your hostname.
Note that validating your hostname, whether that's using the standalone plugin or some other method, is mandatory for all ACME servers, not just Let's Encrypt. Digicerts ACME server also requires a form of validation.
We don't know how you did it the previous time. Using the --server option is usually the correct way to change servers. However, it can be overwritten by an entry in a cli.ini file. Hm, some testing tells me the --server CLI option actually overwrites cli.ini.. So that's not it.