InstallShield: How to alleviate "Another version of this product is already installed..." error

Question

First off, this differs from the question handle "Another version of this product is already installed. Installation of this version cannot continue..." because this is not a development error- my users are seeing this error as well when they try to modify the installation.

Here's the problem: I can install my latest version of the application and everything works fine. However, if I run the same installer again, rather than giving me the maintenance options (Repair/Modify/Remove) I get the above error, the full text of which reads:

Another version of this product is already installed. Installation of this version cannot continue. To configure or remove the existing version of this product, use Add/Remove Programs on the Control Panel.

I can run the uninstall from the Add or Remove programs without incident, but I don't want my users getting this message if they need to fix the installation. I have some custom scripts but otherwise my install sequence is unmodified. When I try to run the verbose logging command, it launches the installer and the error occurs, but no log file is created. That command is foo.exe /verbose".\LogFile.log"

Bumping the revision changes nothing. It will upgrade the first time it's run, but then it displays the same error. I'm using InstallShield 2021 R2.