Hey @Laura
My server typically takes 10+ minutes to rebind to the Web Adaptor after a restart, has this time went by before another attempt? Also, I was curious if you're able to access it through the port URL.
If that's still not working, I'd attempt to restart the IIS server that it's running on, or restart it through the IIS console. If that still does not work, I'd attempt to open up the Web Adaptor configuration through the start menu and attempt to access the URL that is in there, and then if still not working, attempt to place the same URL and see if it's just stuck somewhere.
Hope that helps!
Cody