C. Ovalis browning at leaf base

[gable]

Hello!

I mist the bark every other morning and the leaves daily. the room has 60% humidity on average, so if it is a moisture problem then I reckon it would be down to the medium not holding moisture adequately (the pseudobulb that this problem is occurring with has a bud so I am yet to reply as I don't want to disturb it). I keep it with the others as they have been doing very well where they are.

I don't think sunburn is a problem either given how localised the issue is as I'd expect it to be concentrated where the sun hits the leaf. In addition, the windowsill doesn't get much direct sunlight.

Is it possible that it's a stress response from the small pot?