I think you need to end the line, for nimsuggest to pick up the command.
I once wrote a minimal test program, because of an issue with vscode-nim, which interfaces with nimsuggest via sockets. Idk if it still compiles, but it might help you: [https://github.com/pragmagic/vscode-nim/issues/44](https://github.com/pragmagic/vscode-nim/issues/44)
