I've noticed on TC where there is crowding from closely-spaced canes and trained laterals, that some "spurs" do not grow but a few inches to a foot or so, and then wither and die.

This cane was cut to 2ft after rooting. Then it turned ashy. I cut that part off and brought it in. The rear of the old cane got leaves flower and 1fruir then I saw this week it too had shriveled and died. Meant to cut it v4 vacation but didn't. Can cut it when get back tomorrow night. It's raining at gone anyway you're bit supposed to cut when wet.