snap, av's grow from the center of the
plant and the leaves that are the oldest (and first to die) will be 'underneath'. that's the normal growth pattern
it's also a constant thing - at least in my experience. when i see new growth at the center, i know i'll be seeing some of the older/larger leaves dieing off.
if you have dead leaves, you should have new growth too. sometimes they slow down with the growth and sometimes they take a break from flowering - all totally normal.
do you have enough water in the pot so that the insert is immersed in it? is the insert unglazed? on the inside as well as the outside? a bit of glazing around the top rim (of the insert) is okay.
the soil isn't going to look wet, it will feel slightly moist tho. if you've missed a refill and the soil goes totally dry, you'll need to refill and let the soil become remoistened. or, maybe there's a crack in the base and the water is leaching out instead staying in there for the
plant to drink?
also, when you redid the soil, did you use av potting mix? it should be lightly tamped down not packed solid...the roots need breathing room.
could you post a pic of it? side view as well as from above.
oh, another thing: did you move it to a new location right before you started having problems?