Neo hybrid leaf/stem infection?

[Minimoo]

Hi all,

I’ve been searching the forums, but am not still not sure what’s going on with this orchid. (I’m a total noob to orchids)...

The plant had the small tan spots on the underside of the leaf and some tan areas on the stem when I received it 5 months ago. It has evolved into the pictures below, dropped the second leaf from the bottom, where there seems to be a new fan (?) emerging.

It’s been treated with phyton 27, but the little new leaf is already showing signs of faint spots.

It’s now isolated, but was grown on a NE windowsill behind sheer curtains. Is there any hope?

Thanks in advance!