Add es6 import on code completion not working for npm node_modules even though unexcluded Follow

Hello, I am having trouble getting intellij idea to code complete and automatically add import statements to my javascript module files from es6 module packages installed with npm (specifically the d3.js library). I have the npm packages marked as not excluded and I have turned on unambiguous imports on the fly.

What does work: If I define my own es6 module that exports a function, and then start typing the name of that function in another module in the same project, then idea code completes and adds import statements like import {functionname} from "./...." when I hit enter on autocomplete, exactly as expected.

What doesn't work: When I type the name of a function from an es6 module package installed by npm in node_modules, I don’t get code completion, even though it’s not excluded. But if I type out the function name completely manually, then the function name changes to italics, and if I hit alt-enter, I can select “insert import {select} from "d3-selection";” which adds the import statement correctly. However, I should add that if I do the previous action for a particular function in one js file of a project, and then go to a different js file in the project, now code completion and auto imports works just for that one function (but none others).

Can anyone provide any advice on how to get this to work? Thanks.