Coelgyne Finbriata concerning markings

[Longroots]

So I do think the yellowing is a fertiliser issue. However, the black markings on picture 3 still concern me, as black tissue via fertilisation issues normally come through via solid black tissue die-back, and not these weird rounded markings that is present.

[estación seca]

Coelogyne leaves are very fragile and easily damaged. I suspect that leaf was bumped, scraped or crushed.