In the simplest terms, Vapp is basically Vref with an approach correction, which when everything is working and normal is based on 1/3 the runway headwind wind component (although always within the bounds of minimum 5, max 15). Wind isn’t the full story though, for example with failures there will be further speed corrections to take into account when working out the correct Vapp and pilots are also generally free to add an increment within that range if they feel it appropriate.
VLS does not always equal Vref however, as it is a context sensitive speed (eg the multiplier applied to VS1G changes in different configurations and stages of flight). In Conf Full however, VLS = Vref. In normal day to day operation of the Airbus Vref just isn’t really a commonly used term.
Actually It’s not immediately clear what you have selected in there to be honest - Again the systems just aren’t that particularly high fidelity, so the approach page doesn’t actually quite look like that… in real life it’s much more obvious which configuration you have selected in the approach page as the text will be larger for the selected config (and the landing memo will stop at 3 if conf 3 is selected). That said, the one with the star next to it shows it is selectable, ie not the current selection - While I can’t say for sure since the system just isn’t true to life, that suggests that you have actually got conf full selected in that screenshot.
No idea whether the config in the approach page is selectable in the default I’m afraid as I’ve uninstalled it! That said if you are clicking next to conf 3 (again with airbus user interface logic you would expect the one with the star next to it to be currently inactivate and ready for selection) and nothing changes then I guess not.
It is a great shame that FBW pulled the plug on the Xbox version. Here’s hoping one day it may return or someone else brings a better version to the platform. Asobo’s is nice to look at but that’s about where it ends unfortunately.