Why would some Angular modules import while other do not?

I have a problem with a module that I cant seem to get to import.

pxl-ng-security shows an error in VSCode and VS2019. If I hover over it, it shows error 2307

Here is the import section of the file.

myfile.ts

import { Injectable } from '@angular/core';
import { Headers, Http, Response } from '@angular/http';
import { TokenService } from 'pxl-ng-security';

My tsconfig.json

{
  "compileOnSave": false,
  "compilerOptions": {
    "outDir": "./out-tsc",
    "baseUrl": "src",
    "sourceMap": true,
    "declaration": false,
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "target": "es5",
    "typeRoots": [
      "node_modules/@types"
    ],
    "lib": [
      "es2016",
      "dom"
    ]
  }
}

I have tried using ../../node_modules/pxl-ng-security and it has the same problem. Intellisense sees it and fill it in. I have confirmed that the folder is indeed in that location. I have deleted it from node_modules and done a npm-install -project-local and the module comes back, so it would seem the module is healthy and correct.

Not sure what to look at next?