Central vein turning translucent and spreading

[Rel]

Hello! I'm new to both your forum and the world of orchids in general, but I'm really worried for my favourite little one, and I would love to pick your brains.

I've had a miniature Phalaenopsis for about a year now, and over the last month the central vein of the main leaf has slowly been getting more and more see through. None of the other leaves are showing this, but I'm starting to get some of the bottom leaves dieing off. I'm always very careful to never get water on the leaves.

I'm worried it may be overwatering, but it's on the same schedule it's always been on, albeit with more humidity. I'm also worried it could be something fungal, since I'm currently having a problem with soil fungus in some nearby houseplants.

Here are some pictures:







Sorry, none of them are high quality. You can also see the bit of yellowing on the bottom leaf that I assumed was natural...

Do you have any advice or ideas? I'm excited (and nervous) to here from you!

Thanks!
Rel

[Zoi2]

Hello and welcome to the OB!
What is the humidity where the plant sits?
Joann

[Rel]

Thanks for the quick response!
I don't know exactly, but probably between 60-80%. ...I know that's probably not actuate enough, but it's grouped in with a large number of other plants that are usually pretty moist in a sunny, warm room.