Cannot install Rio 10.3.1 with Webinstall, after uninstalling Offline ISO installed version

Following Remy's advice, https://community.idera.com/developer-tools/general-development/f/using-the-rad-studio-ide/69381/cannot-find-tools-manage-platforms-in-delphi-rio-10-3-1---feature-manager-missing-form-offline-installer, I uninstalled my Delphi 10.3.1 (previously installed with Offline installer - delphicbuilder10_3_1_194899.iso ).

After that, running the webinstaler it keeps saying me that "A previous version of RAD Studio 10.3 was found on your system that need to be uninstalled first...."

Unfortunately there is no other 10.3 left, and I also deleted all the remaining folders as in article: https://community.idera.com/developer-tools/general-development/f/installation-issues-23/68076/manual-uninstall-of-rad-studio-delphi-c-builder-10-3-rio

The webinstal fails on uninstalling and I cannot continue to launch the setup.

Are there any registry keys I should delete manually in order to allow webinstall to continue?

Or what should I do?