@Pathduck Yes, it's a standalone installation, located in a regular folder, not Program Files.
The original installation had a zillion workgroups loaded with tabs. I wanted to start clean but keep the old set-up, so I installed a second copy following instructions from...I don't remember where. It's been working fine for at least several months.
The original is installed in User\xxx\AppData\Local. I don't think I did that, I believe that's where it default installed.
I have Windows Security's controlled folder access on. I have to whitelist individual apps if they get blocked. Is the setup.exe activity normal? If so, should I whitelist it?