About the suggest from VSCode during writing elixir

I tried to use Excrypto module.And I created a project for experimenting.
When I wrote “Excrypto.” in the project, suggests of all of functions of the module were shown.But when I do same thing in my main project, suggests were not shown at all.I confirmed the extensions between two project were same.Tell me the reason of the difference,please.(I’m not good at English,so tell me if there is something unclear.)

What editor extension are you using? I’d recommend ElixirLS. The next thing to check is if there are any errors in the output.

I am using ElixirLS now,but before using this extension,the suggests were shown like this picture.

When vscode showed this,I only used vscode-elixir.there is no error during using vscode,but I don’t know that there is the difference between two project.
In my main project, vscode don’t show any suggest like this picture.

Yeah I wouldn’t recommend vscode-elixir because it is no longer maintained. For ElixirLS have you followed the troubleshooting steps from the readme?