Opening multiple Folders as projects simultaneously

I am using Rider to work on Terraform, which doesn't have an equivalent to a Solution file. If I have no Rider instances open, I can choose File -> Open -> File or Folder and select a file (although I would prefer to select the folder itself) and it will detect the Terraform and list the folder contents.

But, I can't load a second "File or Folder" and have it show up in a new instance of Rider. If I select a file when attempting to open a new folder as a project, the file is opened in the existing instance, even though that's not my goal. I can only ever open one instance of non C# projects.

I've tried:

• Opening C# projects and then choosing "Close Solution", but it closes the entire Rider instance instead of leaving it open or taking me back to the welcome screen.
• Confirming my project open settings are set to new instance or ask.
• Pretending that the Terraform projects are C# by creating an empty ProjectName.sln file at the root of the Terraform project folder.

Please let me know if there is anything I can do to make this work.

Thanks!