Sync Settings fails with Microsoft login and Run as different user

[dbaileyut]

Type: Bug

1. On Windows 11, with 2 sparate AD(on-prem)/Entra hybrid users A and B. VSCode installed using the system installer.
2. Log into Windows with B and configure VS Code settings sync to use Microsoft authentication with A's Entra ID
3. Log into Windows with A
4. Right-click VSCode shortcut and choose "Run as different user"
5. Eventually (guessing after some token expires), the user icon in the left toolbar of VSCode is badged with a "1" and "Sign in to Sync Settings (1)" is listed when you click it
6. Selecting "Sign in to Sync Settings (1)" results in "Unexpected: (pii)"

Error from Settings Sync Output:
025-02-20 12:57:26.432 [error] Unauthorized (UserDataSyncError) syncResource:unknown operationId:06f7c8bf04ba411fb89b7ef6ccdfc6c9: GET request 'https://vscode-sync-insiders.trafficmanager.net/v1/manifest' failed because of Unauthorized (401).
at _h.D (file:///c:/Program%20Files/Microsoft%20VS%20Code%20Insiders/resources/app/out/vs/code/electron-utility/sharedProcess/sharedProcessMain.js:102:22461)
at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
at async _h.manifest (file:///c:/Program%20Files/Microsoft%20VS%20Code%20Insiders/resources/app/out/vs/code/electron-utility/sharedProcess/sharedProcessMain.js:102:19809)
at async bu.createSyncTask (file:///c:/Program%20Files/Microsoft%20VS%20Code%20Insiders/resources/app/out/vs/code/electron-utility/sharedProcess/sharedProcessMain.js:102:132293)
at async Ef.I (file:///c:/Program%20Files/Microsoft%20VS%20Code%20Insiders/resources/app/out/vs/code/electron-utility/sharedProcess/sharedProcessMain.js:109:9218)
at async Ef.H (file:///c:/Program%20Files/Microsoft%20VS%20Code%20Insiders/resources/app/out/vs/code/electron-utility/sharedProcess/sharedProcessMain.js:109:8862)

VS Code version: Code - Insiders 1.98.0-insider (f238618, 2025-02-20T05:04:30.237Z)
OS version: Windows_NT x64 10.0.22631
Modes:

System Info

Item	Value
CPUs	Intel(R) Xeon(R) Gold 6240 CPU @ 2.60GHz (4 x 2594)
GPU Status	2d_canvas: unavailable_software canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: disabled_software multiple_raster_threads: enabled_on opengl: disabled_off rasterization: disabled_software raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: disabled_software video_encode: disabled_software vulkan: disabled_off webgl: unavailable_software webgl2: unavailable_software webgpu: unavailable_software webnn: unavailable_software
Load (avg)	undefined
Memory (System)	16.00GB (5.33GB free)
Process Argv	--crash-reporter-id 3284a01a-7e33-4394-91ef-9d5a546a1ecb
Screen Reader	no
VM	50%

Extensions: none

A/B Experiments

vsliv368cf:30146710
vspor879:30202332
vspor708:30202333
vspor363:30204092
vscod805cf:30301675
py29gd2263:31024238
c4g48928:30535728
a9j8j154:30646983
962ge761:30841072
dsvsc014:30777825
dsvsc015:30821418
2e7ec940:31000449
pythontbext0:30879054
cppperfnew:30980852
pythonait:30973460
dwnewjupytercf:31046870
nativerepl1:31134653
pythonrstrctxt:31093868
nativeloc1:31118317
e80f6927:31120813
iacca1:31150324
notype1:31143044
dwcopilot:31158714
h409b430:31177054
5b1c1929:31184661
6074i472:31201624
dwoutputscf:31238124
customenabled:31241370
hdaa2157:31222309
copilot_t_ci:31222730
f27dg485:31233432
g012b348:31231168
jda6j935:31233686
cp15370_t:31242499
copilothoveron:31237050

[dbaileyut]

Microsoft Authentication trace logs:

Microsoft Authentication.log

"microsoft-authentication.implementation": "classic" is a workaround but use Run as different user quite a bit - hopefully the new method doesn't permanently break that.