What kind of soil are you using? Is it well-draining? I use a mix of perlite, pebble, and fine grade orchid bark for my hoyas at a 1:1:1 ratio. Many of my hoyas leaves are touching (some even partly buried in) the medium, and I have never had a rotten leaf. I am not saying it is your soil, but it is the only thing I can think of. Since the leaves that are touching the soil are rotting, it makes me wonder if the roots are rotting as well. Not sure why they would have a smell.

It's probably a combination of soil that is too water retentive, lack of light to the top of the pot and most importantly lack of air circulation to that area that lead to leaves rotting.

> Should i not pour water directly on top of it?

Some plants would mind that, but not lacunosa.

Older leaves dying is a natural process, but if you leave them there, they do rot with time. This is exactly how plants get fertilizer in nature, one of the ways they get it, anyway. In pots, cleaning out those dead leaves is a good idea before they start rotting.