[Aleksa]

I bought this phal few weeks ago in bloom. I choose it very carefully and it had very green, hard, and healthy leaves. But now, I noticed that those marks have started to appear on bottom leaves, and they softened also. Leaves on top are still healthy. What is this? I suspect on bacterial infection but I hope it isn't because I had some bad experience with bacteria.

I cutted off the flower stalk and repoted plant. Roots are in excellent condition and top 3 leafs are also very healthy. Should I cut off these infected leafs? I know that cutting phal's foliage is not recomended but this looks to be something bad.