Server-side bisect (session rendered pure black, colors=1) pinned it to
plasma-kwin_x11.service timing out and crash-looping: software-GL
compositing init under xorgxrdp never completes at 5160x2160. Fix:
Compositing=false for the RDP accounts (X11-only key, Wayland console
unaffected) + 300s kwin unit start timeout. 12-fix-rdp-bigres.sh now
installs both parts. freerdp harness matrix green across all four flows.
Details: https://projects.knownelement.com/issues/611
Jump-from-iPad showed color bars/cut sides at the big external monitor.
Headless freerdp UAT proved the server clean at 5160x2160 on all codecs
and mid-session resize; mitigation raises the EGFX compressed-frame
budget via systemd drop-in, applied by 12-fix-rdp-bigres.sh (idempotent,
restart-guarded). Human UAT pending.
Detail: https://projects.knownelement.com/issues/611#note-3341
mrcharles