I have had a very low speeds computed by the FACs in the past (G-Dot, S, F).
I went on to check the GW computed by the FACs using the Param Alpha Call Up and the weight during approach was below the DOW which was not possible. (13 tons below the actual weight!!)
We went on to fly the approach using selected speed and managed the speed when configured for landing as we knew the speed wouldn't go below the Vapp target computed from the FMS.
On your picture, you can't even see the VLS, you see the V Alpha Prot.
On the return flight everything was fine and it was the very last time i saw this happen.
I think there was some kind of bug because both FAC were computing about the same really low weight.