Your humidity is a bit low, so I suggest you dont remove the water container. In my experience cheeses continue to lose moisture for quite a while after they go into the cave. As you have such a dry environment it could be that the rind has dried out perhaps a bit too much and has trapped whey inside, which is now seeping through. Does the surface feel damp? The white stuff might be wild mould, which you could rub off with vinegar and salt or leave to see what eventuates. There's lots of information elsewhere on the forum about ageing, with great advice from cheesemakers much more experienced than me.