Another thing to consider that led me to the issue and the confusion, is the difference in opening RT (main) app, vs opening by clicking the RAW file itself:
When opening the app - File Browser, Queue and Preferences - are available; opening the file itself leads to “Remote” mode, where these options are … simply not there, as described on this thread:
So, if you are using Linux - I suggest to use “open with” for the file type - and type in the command: rawtherapee -R , and then every RAW will open in full-mode as well,
as described here:
https://rawpedia.rawtherapee.com/Command-Line_Options
And Thank you to ChasingShadows [Karlheinz Lehmann] for sharing that resource on the linked thread.