Total noob - need help signing CSR with multiple DNS entries with different domains

[xqpvax]

I wish to sign a CSR with a SANS field such as DNS:hostname1.domain1, DNS:hostname2.domain1, DNS:someotherhostname.someotherdomain.

The someotherhostname.someotherdomain is used as a load balanced endpoint and really points to one of the other hostnames listed in the SANS field.

When I sign a CSR with acme.sh, it fails with someotherhostname.someotherdomain is invalid.

As mentioned in the title, this is all new to me so my guess is that acme.sh was installed recognizing 'domain1' but I need recognition of someotherdomain as well?

I've done a lot of reading and frankly, my brain is mush at this point with no success.

Any help would be appreciated.