I had that issue. So you do not check the box to activate Nils but have yes on for the floating panel? Thats what i see to do if there is something else, please let me know.
EDIT...hmm, doing that way ,im getting no notifications. Im doing something wrong.
er, hold on *checks tablet*. make sure you have nils service on in setting>security>notification access
go into NiLS app. turn on Floating panel if not on. if you have lockscreen notifications off, turn them on in setting>security>enable widgets.
that should do it.