Email Reply-To is always principal contact email, was previously blank

Recently upgraded from 2.X to 3.1

The principal contact email (Settings → Journal → Contact) was blank after migration. I filled it in while troubleshooting email that sporadically didn’t arrive.

Now all OJS email seems to have “Reply-To” with the principal contact email address.

I can’t make the field blank again because it is a required field.

Any suggestions on how to restore the original behavior? Perhaps directly edit the database? Or is having “Reply-To” necessary for anti-spam compliance?