Phalaenopsis - Brown mark in stem & Yellow mark in leaf

[mauren]

I have had this phalaenopsis for almost 2 years. I noticed a brown mark in the base of the plant a year ago. I am wondering if this is something bad (maybe a fungus, or bacteria?) because it is extending to the top, and the other side of the stem.

Since the plant has been growing I did not give it a lot of attention. The orchid has had new roots, and it actually started a new leaf few weeks ago.

What alarmed me was that in the back of the new leaf there is a brown blotch, and if you touch it with your finger, it feels bumpy. At the same, another leaf appeared with a yellow mark (with a rough texture to it), and I just saw another leaf with bumps in its surface.

I would appreciate some advice, and if you do so, could you provide details? I am a beginner.

Thanks!