Leaf browning on paphiopedilum

[kasincaptain]

Hello,

I'm not a total novice, but far from an expert. I've got two paphs that I've had for about a year. Don't know the exact variety as they were a gift. They have mottled leaves and deep maroon blooms. Over the last few months, the leaves have started browning at the tips and some have developed brown spots. The only possible cause I can find online for this is insufficient watering. But I keep them regularly watered and they never dry out. Just one of them has also developed a few yellowing leaves. They get good indirect light most of the day. They were/seem to be quite happy overall until recently and are still sprouting new leaves despite the browning and yellowing. I'm at a loss to understand it and would very much appreciate some guidance.