The JSON preview capped a ScrollArea rather than the pre inside it. Radix sizes that viewport in percent, which resolves to the content's own height against a box carrying only a max-height, so a list or dict of any length spilled out of the node panel and the edge popover and painted over the sections below. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01SKL7sUgNWhukDEz95vSMQv