Windows desktop app: PDF preview turns blurry, then freezes when two PDF previews are open

Environment

• Claude Code desktop app, version 2.1.96
• Windows 11 Home 10.0.26200

Summary
When two PDF previews are open in the desktop app's preview panel, the preview first renders blurry, then the viewer freezes completely (no zoom, no scroll, no interaction). With a single PDF open, the preview works fine.

Steps to reproduce

1. In a session, have Claude send/reference PDF file A and open its preview in the side panel.
2. Open a second PDF (file B) so both previews are open.
3. Zoom/scroll in the preview.

Actual behavior

• The rendered PDF becomes noticeably blurry first.
• Shortly after, the viewer freezes entirely: zoom and scroll stop responding. Only closing the previews/restarting recovers.

Expected behavior
Both previews stay sharp and interactive, or at minimum the second preview replaces the first without breaking rendering.

Notes

• The PDFs themselves are valid and unaffected: we byte-compared the generated files across app versions and rendered them externally — identical and fine in system viewers.
• Reproduced consistently during a working session with generated letter PDFs (~1 MB each, embedded images + QR codes).
• Possibly related regression from a recent update: previews now open fullscreen in the panel where they previously opened at panel size.