Let's just hold off on doing anything but watching it very closely. If you want to draw a circle around the edges of the damage area to see if it spreads.

It's looking a little better today. I've looked at it closely and the sunken area is still green and pretty firm, just the tip is dark. I'm wondering if I could have some black tip on it, the tip of the cutting looked a bit darker than normal when I got it but I assumed that was just because it's a darker flower...rest of the stem is hard so if it is any sort of rot I think I can catch it early enough. Gonna leave it for a few more days, hopefully it improves more

This can be a tough time of year to root cuttings. Staying dormant for so long can be hard on some varieties and they get dehydrated. Some of the more sensitive ones can abort tips (black tip). I've had good luck rooting Hilo Beauty in summer.

Well, the bottom looks good so I think it should root (fingers crossed) but I'm worried about some sort of rot spreading down the stem. Again, it doesn't seem to be getting worse but if it is rot I want to catch it as soon as possible

OK, shockingly enough I just checked the container and it has rooted