That doesn't look like Stranglebrand. I have an arborea whose stems split like that. I think it might have to do with uneven watering. Stranglebrand begins as a small lesion surrounded by a dark ring. The tissue browns and softens as it spreads. Stranglebrand does seem to affect mainly yellows but I'm almost positive that's not your problem. I had some great pics of the disease but can't find them. Here's a link to an old post showing an infected plant.

Here is a link that might be useful: Brug with Stranglebrand

I just love coming here and learning more each day. Not sure what is up with this brug, certainly someone with more knowledge will be able to tell you. But after checking up the suspected disease, this isn't SB. I do know that much. :D

Stengelbrand (Stranglebrand)
An incurable fungal disease of multi-hybrids especially those with suaveolens genetics. Yellow are more susceptible. Discoloration usually starts at leaf scars and includes a black ring. Dispose of plant, pot and soil.

I certainly hope I never run across this particular issue! :/

~Tina

I agree with Karyn.. it just looks stressed..

Kylie