Why does VS Code <Alt>+f, o not bring up the open menu

[etkeys]

When no editors are open, <Alt>+f, o will bring up the open menu. Once editors are open though, it'll only switch to an editor or open a new file (if <Alt>+f, n was used to create an editor. This all started after switch to new i3 config. Although I didn't really check after switch to mate-settings-daemon

[etkeys]

Haven't tried the new i3 config on aludra yet.

[etkeys]

Using <Alt>+Arrow Key has the same behavior.

[etkeys]

In VS code. executed Developer: Toggle keybinding ... troubleshooting. Pressing <Alt>+f, o outputted this...

[2021-05-20 20:13:04.135] [renderer1] [info] [KeybindingService]: / Received  keydown event - modifiers: [alt], code: AltLeft, keyCode: 18, key: Alt
[2021-05-20 20:13:04.136] [renderer1] [info] [KeybindingService]: | Converted keydown event - modifiers: [alt], code: AltLeft, keyCode: 6 ('Alt')
[2021-05-20 20:13:04.137] [renderer1] [info] [KeybindingService]: \ Keyboard event cannot be dispatched in keydown phase.
[2021-05-20 20:13:04.292] [renderer1] [info] [KeybindingService]: / Received  keydown event - modifiers: [alt], code: KeyF, keyCode: 70, key: f
[2021-05-20 20:13:04.293] [renderer1] [info] [KeybindingService]: | Converted keydown event - modifiers: [alt], code: KeyF, keyCode: 36 ('F')
[2021-05-20 20:13:04.293] [renderer1] [info] [KeybindingService]: | Resolving alt+F
[2021-05-20 20:13:04.294] [renderer1] [info] [KeybindingService]: \ No keybinding entries.
[2021-05-20 20:13:04.643] [renderer1] [info] [KeybindingService]: | Resolving ctrl+O
[2021-05-20 20:13:04.644] [renderer1] [info] [KeybindingService]: \ From 3 keybinding entries, matched extension.vim_ctrl+o, when: editorTextFocus && vim.active && vim.use<C-o> && !inDebugRepl, source: user extension vscodevim.vim

[etkeys]

From Default Keybindings

{ "key": "ctrl+n",
"command": "extension.vim_ctrl+n",
"when": "editorTextFocus && vim.active && vim.use<C-n> && !inDebugRepl || vim.active && vim.use<C-n> && !inDebugRepl && vim.mode == 'CommandlineInProgress' || vim.active && vim.use<C-n> && !inDebugRepl && vim.mode == 'SearchInProgressMode'" },
{ "key": "ctrl+o",
"command": "extension.vim_ctrl+o",
"when": "editorTextFocus && vim.active && vim.use<C-o> && !inDebugRepl" },

[etkeys]

Running Developer: Toggle Keyboard Shortcut Troubleshooting on Windows

[2021-05-24 08:10:24.517] [renderer1] [info] [KeybindingService]: / Received  keydown event - modifiers: [alt], code: AltLeft, keyCode: 18, key: Alt
[2021-05-24 08:10:24.517] [renderer1] [info] [KeybindingService]: | Converted keydown event - modifiers: [alt], code: AltLeft, keyCode: 6 ('Alt')
[2021-05-24 08:10:24.517] [renderer1] [info] [KeybindingService]: \ Keyboard event cannot be dispatched in keydown phase.
[2021-05-24 08:10:24.749] [renderer1] [info] [KeybindingService]: / Received  keydown event - modifiers: [alt], code: KeyF, keyCode: 70, key: f
[2021-05-24 08:10:24.750] [renderer1] [info] [KeybindingService]: | Converted keydown event - modifiers: [alt], code: KeyF, keyCode: 36 ('F')
[2021-05-24 08:10:24.752] [renderer1] [info] [KeybindingService]: | Resolving alt+F
[2021-05-24 08:10:24.759] [renderer1] [info] [KeybindingService]: \ No keybinding entries.
[2021-05-24 08:10:25.292] [renderer1] [info] [KeybindingService]: + Storing single modifier for possible chord alt

VS Code info

VS Code: 1.56.2 (user setup) 
Commit: 054a9295330880ed74ceaedda236253b4f39a335
Date: 2021-05-12T17:13:13.157Z
Electron: 12.0.4
Chrome: 89.0.4389.114
Node.js: 14.16.0
V8: 8.9.255.24-electron.0
OS: Windows_NT x64 10.0.19042

VSCodeVim: 1.20.3

This appears to be an issue with keybinding detection and is not an upgrade show stopper.