Dendrobium Hibiki care

[elenfr]

Hello

I recently purchased a Dendrobium Hibiki online – my first orchid beyond a couple of phals. It came in a 6cm pot and, though my understanding is that dendrobiums like to be potted small, this plant seems particularly large for its pot. Would re-potting it into a slightly larger pot be sensible?

A second question: a leaf with browning at the base and yellowing elsewhere has fallen from the plant. A couple of other leaves have some yellowing on the tips. What might be the cause of these issues? I am keeping the plant (along with two other newly-bought dendrobiums I may soon ask about!) in a south-facing window in the UK, and though I have for the most part been diligent in closing the window's shaded curtain when the clouds have parted, I may have been tardy on occasion. Could this be the cause?

Many thanks in advance for any guidance.