Hi @ohilbig01,
Locally I am using the GitHub and latest branch stable-3_3_0, and I cannot reproduce it, but I could reproduce it in the OJS Test Drive which uses 3.3.0.14, as you said.
I think this issue was fixed within this issue: pkp/pkp-lib#6293 consider urnCheckNo setting, fix checkDuplicate in PubIdPlugin by bozana · Pull Request #3897 · pkp/ojs · GitHub, and is available from 3.3.0.15 on.
Best,
Bozana