The child graph breakdown showed adam=-1.0ms because it was measuring elapsed(backward_end, adam_end) where adam_end is from the OLD phase timing system, not the adam child graph. Added proper adam_child_end event recorded after the adam_child launch. This will reveal the actual adam_child GPU time — currently suspected to be 3117ms (73% of step time) based on total - measured children. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>