I have a few young chestnut trees and I noticed this the other day on one (photo 1). It reminds me of a nutrient deficiency problem but I can’t find anything on the interwebs that really looks the same. At first glance it looks like insect damage but the pattern is too regular.
All five of my 3rd-leaf trees have struggled, dying back to the graft if there is one, or just dying back to ?, if they are a seedling. I may have lost one this year which has been super vigorous before but dies back some every year, only to make many shoots the next.
This unit (photo 2) is a Toka plum. It got some kind of die-back disease this year (I don’t recall at the moment) but I had seen this damage (shown) on it earlier. There is some ooze on the same branch; may be related, maybe not. I’m concerned about the lesion…I’ve seen a few of them. Any ideas ??