Cotoneaster with a red branch

[brentwood]

Repotted this in all pumice early spring, from a nursery pot, fair amount of root work. Starting to bloom now, but I noticed one completely red branch, a little bit of red leaves elsewhere - not brown, at least not yet. Maybe some mites. Sprayed bonide antifungal last week, hit up with Neem today - any thoughts on the red, kneejerk reaction is to think fire blight with these.
Mostly full sun, although that is probably considered dappled to someone that doesn't live in the woods.
Thanks!

B

 

[Eckhoffw]

Is it possible that the colors are from die back, or stress on that branch?
Is it still actively growing?

 

[brentwood]

Is it possible that the colors are from die back, or stress on that branch?
Is it still actively growing?

This happened pretty quickly, I'm still looking for the direction is going -growth vs dieback. I probably worked it pretty hard to get into that basket, but it's been largely lefty alone for the last 3-4 weeks. I probably stressed it at least a little. It's still got a fair amount of dead branches from when I got it, looking for rot /wood to remove over the next year. Worry that part has the possibility of becoming a disease entry point.

B