Keymap editing doesn't seem to work on Ubuntu

[VivekChugh]

I am using sublime text on Ubuntu 20.04. Plugin got installed properly. Works fine.

But I Wanted to modify shortcut to get 'search window' from Ctrl+Alt+? to Ctrl+? so that it is easier to input

did CtrlAlt⇧⏎ to Open .sublime-keymap File For Editing

Got following pop up.

it creates new keymap file in user/ directory

I added
[
{
"keys": ["ctrl+?"], "command": "find_keymap"
}
]

restarted sublime text.

find_keymap didn't work, rest of the keymap Keyboard shortcuts stopped working too.

Had to remove newly create keymap file to restore functionality