Clipboard history selections passed the full selected text as a process argument to omarchy-clipboard-paste-text. Large entries can exceed Linux's per-argument exec limit, so the helper never starts reliably for big copied blocks.
Pass the original history index instead and have the helper read that entry from clipboard-history.json before wl-copy and Shift+Insert. Also focus the first row when opening the manager, keep filtered rows mapped to their original history indexes, and drop whitespace-only text entries.
David Heinemeier Hansson