What is important is not just the dev tool GUI version number (the interface), which number shows in pressing the “About” button, but also the actual OXR version number which shows with the headset plugged in in the Status tab instead.
This is where regardless of the GUI front-end version, you’d know whether you’re running the latest (was 104.) or the preview version (was 105.)
It in selecting “Use Preview” version the number is higher (says 106.xxx) then there has been an update indeed.