Phal. soft rot?

[knewt]

Hi
New here, and my first post - I just wish it didn't need to be in this sub-forum.
I live in NW Florida, and our house is not centrally heated, so some nights it gets around to 60º by morning.

I'm mostly OK with plants, but only have a few orchids.
Last week I decided to increase my collection, and bought a couple cheap plants from the discount shelf in Lowes.

One of them was this Phal. NOID - Pretty dried up looking, well past spike, in a decorative pot.
After letting it soak overnight, when I repotted (bark mix, with some added sphagnum), I was thinking how good the roots looked - Still fat and green. So I had high hopes.

Anyway, I noticed this leaf, this morning - Something I'm pretty sure wasn't there a couple days ago.
It looks like some photos of soft rot I've seen, but I don't want to over-react, and throw the baby out with the bathwater, as they say.

All I have to work with right now, is cinnamon and peroxide - Not great, but if there is something I can do to help or stop it, I would appreciate any advice.
Thank you.