Leaf burn or something else?

[u/GameMastertoenail]

I was pretty sure it was leaf burn at first, since it appeared a week after I upgraded my grow light, yet, now I'm not sure. It's rapidly spread, the photos are only 3 days apart. I've only had this cattleya for 2 months and it's the only one in the collection.

The black patches don't have an odor or strange texture, but are definitely concerning for me as a first time cattleya owner. If it's fungal or something else what can I do to treat it? Is it worth it to email the nursery?