It seems that Hub only checks the project versions on launch and never again. If you checkout a different branch of the project that is using a different version of Unity, Hub tries to open it with the wrong version, even if the correct/matching version is installed.
Steps to reproduce:
- Clone a project that is using git and has been updated to newer version of Unity during development.
- Checkout the most recent master commit that is using a recent Unity version.
- Add the project to Hub and open it. It will open it with the recent Unity version.
- Close the Editor.
- Checkout an older commit that is using an older Unity version.
- Go back to Hub. Notice that the project version was not updated.
- Open the project.
Expected result:
Hub opens the project using the already installed and matching older Unity version.
Actual results:
Hub will ask you if you want to upgrade the project to the newer version.
Suggestion:
Update the project version when the Hub window gets focus.