Chat automatically returns to Claude Opus 4.6 Fast mode

[Torva86]

Type: Bug

In my chat session, whatever agent i select, for example i select GPT 5.3 Codex, once i hit enter it will automatically switch to Claude Opus 4.6 fast mode 30x and process the chat with it even tho i selected GPT. Its the first time doing this since the update of this morning.

VS Code version: Code 1.111.0 (ce099c1, 2026-03-06T23:06:10Z)
OS version: Windows_NT x64 10.0.19045
Modes:

System Info

Item	Value
CPUs	AMD Ryzen 7 3700X 8-Core Processor (16 x 3593)
GPU Status	2d_canvas: enabled GPU0: VENDOR= 0x10de, DEVICE=0x1f06 [NVIDIA GeForce RTX 2060 SUPER], DRIVER_VENDOR=NVIDIA, DRIVER_VERSION=32.0.15.8115 ACTIVE GPU1: VENDOR= 0x10de, DEVICE=0x1f06 [NVIDIA GeForce RTX 2060 SUPER], DRIVER_VERSION=32.0.15.8115 GPU2: VENDOR= 0x10de, DEVICE=0x1f06 [NVIDIA GeForce RTX 2060 SUPER], DRIVER_VERSION=32.0.15.8115 GPU3: VENDOR= 0x10de, DEVICE=0x1f06 [NVIDIA GeForce RTX 2060 SUPER], DRIVER_VERSION=32.0.15.8115 GPU4: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.19041.5794 Machine model name: Machine model version: direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off trees_in_viz: disabled_off video_decode: enabled video_encode: enabled webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	31.94GB (22.02GB free)
Process Argv	--crash-reporter-id 370e9266-e9f8-49bf-b3f2-6c65f5433e38
Screen Reader	no
VM	0%

Extensions (3)

Extension	Author (truncated)	Version
dart-code	Dar	3.130.1
flutter	Dar	3.130.0
copilot-chat	Git	0.39.0

(2 theme extensions excluded)

A/B Experiments

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[lramos15]

Well that's not good.

Restarting VS code doesn't do anything? What if you select Auto.

Can you attach a screen recording please

[Torva86]

Already tried to restart VS code also the ocmputer
Auto still choose the fast mode Claude
Here is the screen record https://youtu.be/gGuEdbZclW8

[Torva86]

I fixed the problem by going in "Manage Models..." and then Hide Claude Opus 4.6 (fast Mode) (Preview) and this fixed the problem of always going back to this one. Now i can use other models.

Still a bug tho.

[patschmitt91]

Hey @lramos15! Just experienced the same bug @Torva86 reported. Hiding Claude Opus 4.6 from my model list worked as a temporary workaround.

That said, I just tried to select GPT5.4 as my model and it looks like it still defaulted to auto.