Thank you for the provided project.
I have tested it and everything worked as expected on my end (a clean Windows 10 machine).
Here are the test websites I've got in IIS Manager:
When the setup was launched, you can see that all 3 websites were inserted into the ComboBox control (even though for my test website I have more than one binding):
I have then selected the test website having the port no. 80, and its' URL was correctly inserted into the Static Text control:
In order for me to further investigate this, could you please forward me:
- a screenshot of your websites in IIS Manager
- an installation log
of this test setup (created with the project you have attached)