You have a firmware version 4.4. Firmware version displayed at the bottom is taken from the browser cache and will be updated as soon as you press Ctrl+F5.
Yes, as Andril says, the 3.5.5 text that you’re seeing at the bottom of the screen is old/cached browser content, and if you force your web browser to refresh, that too will get updated.
However, while you are upgrading, I’d take that right to 4.4.1-RC5 if I was you. I know 4.4.1-RC5 is technically a Beta release, but there are some fixes in 4.4.1 which are pretty much mandatory to stop some 4.4 weirdness(es) so that’s what we are deploying in production.