If you’re using the stable version, delete it. And install the experimental custom fbw version. That should solve the flight dynamics issue.
Your approach speed in relative to your weight should be automatically calculated by the MCDU. The VLS is your minimum allowed speed before you stall, and the Approach speed or VAPP on full flaps configuration should generally show 5 knots above the VLS. Just follow that speed and you should be good.
Myself, personally, though I always set my VAPP to be 10 knots above VLS. For me it’s a lot more stable and easier to land. Here’s a recording of my landing just a few hours ago.
