I am new user of Power Automate Desktop. I turned on "Power Fx Preview" on my first flow, just because why not, and then was puzzled that the list of actions was missing many items. Is this selection a "one time only" thing and cannot be reversed? Is it supposed to remove a whole bunch of actions because only certain ones support "Power Fx" (whatever that is).
At first I assumed it was a subscription level issue as I am using the desktop version as a non business MS Office 365 / Win 11 Pro user. But it appears the issue is the setting for Power Fx.
For example under Variables I only have this list

If I create another flow and do not select the Power FX Preview option I see a much longer list of actions:
