Comment toggling in VSCode always using block comments

I couldn't toggle line comments with // until I changed
"comments": {
    "lineComment": ["//", "*"],
    "blockComment": ["/*", "*/"]
}
to
"comments": {
    "lineComment": "//",
    "blockComment": ["/*", "*/"]
}
in language_config.json, not sure if that's a general issue or where language_config.json is stored (couldn't find it in the repo). Thanks for the resource!!