Oncidium with rusty ring markings

[Edew]

Hi lovely orchid enthusiasts,

I need your help. Does this look like a virus? Or is it just lack of humidity doing a number on the older leaves?

This is Oncidium Aka Baby ‘Raspberry Chocolate.’ I know Oncidiums are known for having black spots on their leaves when grown in low humidity, but these look different from that.

The new growths seem to be good and healthy so far.

Thank you!