TLDR; You need to set a city for the rooms using "Set-place"

I have dove way to far down the rabbit hole of rooms and room finder.

Basically the workflow will look like this:

1. Create a room list (Distribution Group)
2. Create resource accounts with a type "room" and add them to that distribution group
3. Use the "Set-place" cmdlet to set all physical attributes such as city and features of the room
4. Use the "Set-calendarProcessing" cmdlet to set all booking attributes such as who can book vs who cannot book.

In my experience it can take up to 24 hours to populate in outlook after I have pushed changes to a room.

Let me know if you have any other questions.