WebRTC Spatial voice sometimes cannot be heard from someone in an adjacent region

[Dan-Linden]

Environment

Second Life Release 7.1.11.11074622243 (64bit) Release Notes

You are at 128.0, 128.0, 23.0 in webRTC1 located at simhost-07c23d76c83837d55.aditi
SLURL: secondlife://Aditi/secondlife/webRTC1/128/128/23
(global coordinates 259,968.0, 245,376.0, 23.0)
WebRTC-Voice 2024-09-30.11111372425
Release Notes

CPU: Intel(R) Core(TM) i7-5930K CPU @ 3.50GHz (3491.91 MHz)
Memory: 32610 MB
OS Version: Microsoft Windows 10 64-bit (Build 19045.4894)
Graphics Card Vendor: NVIDIA Corporation
Graphics Card: NVIDIA GeForce GTX 1080/PCIe/SSE2

Windows Graphics Driver Version: 32.0.15.6590
OpenGL Version: 4.6.0 NVIDIA 565.90

Window size: 1712x1217
Font Size Adjustment: 96pt
UI Scaling: 1
Draw distance: 128m
Bandwidth: 3000kbit/s
LOD factor: 1.375
Render quality: 3
Texture memory: 8192MB
Disk cache: Max size 1638.4 MB (26.4% used)

J2C Decoder Version: KDU v7.10.4
Audio Driver Version: OpenAL, version 1.1 ALSOFT 1.23.1 / OpenAL Community / OpenAL Soft: OpenAL Soft
Dullahan: 1.14.0.202408091639
CEF: 118.4.1+g3dd6078+chromium-118.0.5993.54
Chromium: 118.0.5993.54
LibVLC Version: 3.0.21
Voice Server Version: Secondlife WebRTC Gateway

Packets Lost: 0/270 (0.0%)
October 11 2024 13:06:29

Description

Spatial voice does not work reliably for users that log into adjacent regions.

Reproduction steps

Repro: (this is not a reliable repro

1. UserA (testerd5) logged into WebRTC1 on Aditi (Windows 10, 7.1.11.11074622243 ExtraFPS)
2. UserB (testerd1) logged into WebRTC2 on Aditi (Windows 11, 7.1.11.11074622243 ExtraFPS)
3. UserA and UserB cannot hear each other across the region boundary
4. UserB crossed into WebRTC2
5. UserB can see their own voice waves.
6. UserB cannot hear or see voice waves from testerd5.

Viewer logs with debugging enabled:
UserA WebRTC1 SecondLife.log

UserB WebRTC2 to WebRTC1 SecondLife.log