I am assuming you have updated your Argon to 0.9.0 – you’d want to do that first, to get rid of the pesky bug I mentioned above (which could possibly interfere with you getting your Xenons set up).
If you’ve done that, can you try setting up the Xenons again? (Make sure you have the latest version of the mobile app – 2.3.11.)
If that doesn’t work—
If your Xenons were on-line and happy, the next time you flashed user firmware (“app”) to the devices, it would update Device OS to what you have displayed in your screenshot – in this case, 0.9.0. But if they’re not, you’ll have to use CLI to flash 0.9.0 to them.
I don’t think that particle update works with the Gen3 devices yet. See my instructions in this post about flashing Device OS, Tinker, and the bootloader (in that order) to the devices, but of course replace the “argon” in the file names/command lines with “xenon”.