Unable to select Sharing Only user when setting up file sharing

I have this weird issue on Sonoma where after creating a sharing-only user I'm unable to select it under Windows File Sharing. Instead I only see an entry for my main account (+ other Standard/Admin accounts), which is sometimes duplicated: Creating a second sharing-only account just results in yet another duplicate of my main, and so on: This occurred both before and after a full factory reset (OS + data).