Switching to Agent mode from Plan erases prompt

[praeclarum]

Type: Bug

Repro:

1. Enter a prompt in plan mode. Submit it.
2. Wait for the AI to respond.
3. Write new prompt instructions.
4. Switch the mode to "Agent".
5. BUG: your prompt is erased and "Start implementation" is sent instead. The prompt is not available in the prompt history either. Just nuked.

Expectation 1: changing modes should not cause a submit
Expectation 2: my prompt should never be erased

VS Code version: Code 1.119.1 (974500e64f0d1cfdf7c9821a2a51c2cb3bf0e561, 2026-05-12T01:20:22+09:00)
OS version: Darwin arm64 25.4.0
Modes:
Remote OS version: Linux x64 6.8.0-101-generic

System Info

Item	Value
CPUs	Apple M4 Pro (14 x 2400)
GPU Status	2d_canvas: enabled GPU0: VENDOR= 0x106b [Google Inc. (Apple)], DEVICE=0x0000 [ANGLE (Apple, ANGLE Metal Renderer: Apple M4 Pro, Version 26.4.1 (Build 25E253))], DRIVER_VENDOR=Apple, DRIVER_VERSION=26.4.1 ACTIVE Machine model name: Mac Machine model version: 16.11 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: enabled_on trees_in_viz: disabled_off video_decode: enabled video_encode: enabled webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	3, 3, 3
Memory (System)	64.00GB (0.44GB free)
Process Argv	--crash-reporter-id fb2d1ee8-a95f-4e95-9f19-9a4ef23bb040
Screen Reader	no
VM	0%

Item	Value
Remote	SSH: kaon.local
OS	Linux x64 6.8.0-101-generic
CPUs	Intel(R) Core(TM) i5-10600K CPU @ 4.10GHz (12 x 3701)
Memory (System)	62.71GB (54.40GB free)
VM	0%

Extensions (85)

Extension	Author (truncated)	Version
copilot-chat	Git	0.48.1
github-copilot-llm-gateway	And	1.0.4
vscode-dbf	ape	0.1.2
alexa-skills-kit-toolkit	ask	2.16.0
gltf-vscode	ces	2.5.1
doxdocgen	csc	1.4.0
yash	dao	0.3.1
racket	Dmy	1.2.0
binary-plist	dni	2.0.0
metal-shader	dou	1.0.5
vscode-wasm	dts	1.4.1
bson-viewer	Dud	1.1.2
prettier-vscode	esb	12.4.0
esp-idf-extension	esp	2.1.0
vscode-github-actions	git	0.31.5
vscode-pull-request-github	Git	0.144.0
vscode-graphql	Gra	0.13.4
vscode-graphql-execution	Gra	0.3.4
vscode-graphql-syntax	Gra	1.3.10
vscode-power-mode	hoo	3.0.2
ilspy-vscode	ics	0.24.0
better-cpp-syntax	jef	1.27.1
copy-markdown-as-html	jer	1.1.0
cmake-language-support-vscode	jos	0.0.9
vscode-cudacpp	kri	0.1.1
lldb-dap	llv	0.4.1
bison	lun	0.1.0
rainbow-csv	mec	3.24.1
ninja-syntax	mel	1.0.0
vscode-containers	ms-	2.4.4
vscode-docker	ms-	2.0.0
csdevkit	ms-	3.20.197
vscode-dotnet-runtime	ms-	3.0.2
debugpy	ms-	2026.7.11331008
isort	ms-	2026.4.0
python	ms-	2026.4.0
vscode-pylance	ms-	2026.2.1
vscode-python-envs	ms-	1.30.0
jupyter	ms-	2025.9.1
jupyter-keymap	ms-	1.1.2
jupyter-renderers	ms-	1.3.0
vscode-jupyter-cell-tags	ms-	0.1.9
vscode-jupyter-slideshow	ms-	0.1.6
remote-containers	ms-	0.459.0
remote-ssh	ms-	0.122.0
remote-ssh-edit	ms-	0.87.0
remote-wsl	ms-	0.104.3
cmake-tools	ms-	1.23.52
cpp-devtools	ms-	0.5.13
cpptools	ms-	1.32.2
cpptools-extension-pack	ms-	1.5.1
hexeditor	ms-	1.11.1
makefile-tools	ms-	0.12.17
mono-debug	ms-	0.16.3
remote-explorer	ms-	0.5.0
vscode-serial-monitor	ms-	0.13.1
vscode-speech	ms-	0.16.0
vsliveshare	ms-	1.1.122
vscode-stl-viewer	mts	0.3.0
ufmt	omn	2025.11.5
vscode-jest	Ort	6.4.4
vscode-nuget-gallery	pat	1.2.5
wgsl	Pol	0.1.17
java	red	1.54.0
vscode-xml	red	0.29.2
llvm	RRe	0.2.0
partial-diff	ryu	1.4.6
modelica	Sim	0.0.4
fish-vscode	sky	0.2.1
shader	sle	1.1.5
urdf	smi	0.3.0
swift-vscode	swi	2.16.4
even-better-toml	tam	0.21.2
pdf	tom	1.2.2
cmake	twx	0.0.17
nisaba	UCL	1.4.2
vscode-lldb	vad	1.12.1
deepseek-v4-for-copilot	Viz	0.5.0
vscode-java-debug	vsc	0.59.0
vscode-java-dependency	vsc	0.27.3
vscode-java-pack	vsc	0.30.5
vscode-java-test	vsc	0.45.0
vscode-maven	vsc	0.45.3
vscode-cil-complete	wk-	0.0.5
material-theme	zhu	3.19.0

(3 theme extensions excluded)

A/B Experiments

vsliv368cf:30146710
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
6abeh943:31336334
envsactivate1:31505457
cloudbuttont:31379625
3efgi100_wstrepl:31403338
ec5jj548:31422691
cp_cls_t_966_ss:31454198
inlinechat_v2_hd992725:31505030
c3h7c220:31478652
38bie571_auto:31426784
cp_cls_c_1081:31454833
conptydll_true:31498968
ia-use-proxy-models-svc:31452481
e9c30283:31461165
test_treatment2:31471001
46204921:31447328
control_6dc23131:31513471
idci7584:31464702
e3e4d672:31494082
ei9d7968:31496641
nes-extended-on:31455476
chat:31457767
8hig5102:31480529
89g7j272:31507493
7e187181:31503455
i2gc6536:31499202
52612955:31515327
ghj88844:31499326
h08i8180:31475369
ddid_c:31478207
1b2f8594:31514983
getcmakediagnosticson:31489824
g_d1382936:31515467
7df3h592:31512476
pro_large_t:31499376
cp_cls_c_1082:31504161
logging_enabled_new:31498466
j0d79568:31499440
jb_cp_cls_c_632:31510883
56dj4588:31512888
cg448276_tst_on:31514358
32d76977:31512328
ha629193:31508444
539gd155_c:31506875
api_cot_ctrl:31513533

[vs-code-engineering]

Thanks for creating this issue! It looks like you may be using an old version of VS Code; the latest stable release is 1.120.0. Please try upgrading to the latest version and checking whether this issue remains.

Happy Coding!