Description
Symptom: on 2026-08-01 the Rupelmonde kiosk (peppy-dumpling-32) streamed rupelmonde-castle-viewer with perfect video and audio, but the yellow hotspot bulbs could not be clicked. Four sessions between 13:01 and 14:59, each with repeated clicking and no response.
Which body: all four sessions launched against 10.10.100.12 = cosmic-pretzel-98 (cloud-seven), NOT the local Rupelmonde body. boom-pickle-38 was offline, so head discovery failed over cross-venue.
Client side is clean (ruled out):
- Stream 1920x1080, Moonlight window 1920x1080, so the video region is the whole window and coordinates map one to one.
- Absolute (remote desktop) mouse mode was active.
- 38 to 70 mouse button events logged per session in the Moonlight log.
- The exit overlay hit test logged hit=0 for every click, so the overlay did not consume them. They reached the normal LiSendMouseButtonEvent path.
- Visitor click coordinates cluster around (964,375), which lines up with an actual yellow bulb at roughly (960,422). They were aiming correctly.
Root cause (confirmed by live reproduction on 2026-08-02):
cosmic-pretzel-98 has THREE Virtual Display Driver adapter instances installed, not one:
ROOT\DISPLAY\0000, ROOT\DISPLAY\0001, ROOT\DISPLAY\0002 (all Status OK)
and correspondingly three VDD monitors plus the physical monitor:
DISPLAY\MTT1337\1&28A6823A&0&UID256 (VDD)
DISPLAY\MTT1337\1&33320F0&0&UID256 (VDD)
DISPLAY\MTT1337\1&15ECD195&0&UID256 (VDD)
DISPLAY\TCT0270\5&33A96493&0&UID8450 (physical DP1080P60)
C:\Sunshine\config\display_device.state records the resulting topology as four independent groups, which means an extended desktop across four monitors:
[{f8eb32ab-...}] physical
[{5eb52002-...}] VDD, this is output_name in sunshine.conf
[{9acddf6d-...}] VDD
[{6f40d39e-...}] VDD
Sunshine captures {5eb52002-...} and makes it primary, which is why video is correct (verified: hydrabody debug screenshot during a live stream returns a 1920x1080 image of the castle). But absolute mouse coordinates from Moonlight are normalized against the whole virtual desktop, which now spans roughly four monitors. Clicks therefore land far from where the visitor aimed, on a different display entirely. Video and audio look perfect and nothing is clickable, which is exactly the reported symptom.
Note vdd_settings.xml correctly says monitors count = 1. That count is per driver instance, so three instances still produce three monitors.
Proposed fix:
1. Remove the two extra Virtual Display Driver adapter instances so exactly one remains.
2. Delete C:\Sunshine\config\display_device.state so Sunshine re-derives a clean topology (this is the documented step after any VDD device disable or enable).
3. Verify with a stream that the hotspot bulbs respond.
4. Audit the other bodies for the same duplicate VDD instance condition, and consider having hydrabody detect and report more than one VDD adapter instance as a health problem, since the failure mode is silent.
Also worth addressing separately: boom-pickle-38 (the Rupelmonde body) is offline and still offline as of 2026-08-02. Cross-venue failover then sent visitors to a body with this defect.