Quirk with "anyone can view" links

I checked for Limited Access User Permission Lockdown Mode and found it was on. I certainly found at least some of what it does--with it on, PDFs open however the browser you're using likes to handle PDFs, with it off, it opens with SharePoint's modern-experience document viewer (this was with a dummy user with no permissions to the site the documents came from).

My dummy user wasn't seeing the issues reported to me either way. I didn't get much information from users about what happened leading up to them having these issues, so I won't know if I'm in the clear quite yet, but at least I can say I have a known source of bugs eliminated. Thanks, Stephen!