Struggling with Black Bamboo — would appreciate advice

I want to be honest: I'm not getting great results with Black Bamboo and I'm not entirely sure why. new canes not reaching full height in the first year has been a recurring problem despite my attempts to address it. I've been focusing on removing the oldest and most congested canes each spring based on everything I've read.

rapid establishment and fast vertical growth is there in glimpses, which tells me the plant has potential in my conditions. I have it in a windbreak planting in an exposed position which might not be ideal. foliage refresh as older leaves shed in late winter showed some improvement. Two stars for now — not the plant's fault, but not a success yet. I'll update if things improve.