Hi @Shamyog
From the screenshot it seems you are using OWA (Outlook on the web).
Based on my test, the Recent buildings is a feature based on the past selections of the current mailbox.
Which means, if the account hasn't booked the a room via the roomlist before, the roomlist would not appear automatically in the Recent buildings.
And according to this link: How to configure the new Room Finder in Outlook
currently it is not be possible to see all the roomlists.
As a workaround, have you tried setting the city value for the rooms in the roomlist?
Once you set the city value for the rooms, you should be able to see the roomlists via cities under All cities.
Please note that it may take sometime (up to 24 hours) for the changes to take effect.
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