round orange-brown spots at leaf base

Need advice!

The plant is growing well and with me since november. As the leaves of the two growths grow from the base of the plant, there appeare this orange and round depressed spots, that beginn well down in the fan. Once they 'surface' there is no more spreading, they kind of dry up.
I've looked many pages with paph diseases, but none does match.
The plant is a Paph. Moustache, growing surprisigly quick comparing with other Paphs with two leading growths and three new little ones.

As it seems it isn't spreading I just removed the pot from the rest of plants but didn't treat it so far. It's now on the drier side and even more ventilated.

Any suggestions, please?

This is heat stress. I had one before. It dry too much and the temp was warm. It never did spread. Observe it and see if it will spread out.

I agree with the above. They look like sunburn to me.

the growth in the first pic looks a little pale. are you feeding it enough?

Heat stress could be! If the spots origin is about three weeks or four ago, that could well be! Thanks!

No sunburn though, cause the spots 'grow' when still beneath the older leaf - see the arrow? There is a third spot beneath the outer leaf, shining through.

I don't feed much actually, but the pale color is due to the photo - the plant is grassgreen.

The light color could be from light stress/to much light. That may give you the heat stress.