Vue2 with pinia fails to start instance - vue.js

Question

I decided to use Pinia with my vue2 project but it fails once I load the page.
Error:
TypeError: Object(vue_demi__WEBPACK_IMPORTED_MODULE_0__["effectScope"]) is not a function. (In 'Object(vue_demi__WEBPACK_IMPORTED_MODULE_0__["effectScope"])(true)', 'Object(vue_demi__WEBPACK_IMPORTED_MODULE_0__["effectScope"])' is an instance of Object)
createPinia — pinia.mjs:955
packages.json
{
"name": "frontend",
"version": "0.1.0",
"private": true,
"scripts": {
"serve": "vue-cli-service serve",
"build": "vue-cli-service build",
"lint": "vue-cli-service lint"
},
"dependencies": {
"chart.js": "^3.9.1",
"core-js": "^3.6.5",
"datatables.net": "^1.11.3",
"datatables.net-dt": "^1.11.3",
"driver.js": "^0.9.8",
"jquery": "^3.6.0",
"pdfjs-dist": "2.15.349",
"pinia": "^2.0.22",
"vue": "^2.6.11",
"vue-chartjs": "^4.1.1",
"vue-tour": "^1.5.0",
"vuedraggable": "^2.24.3"
},
"devDependencies": {
"#vue/cli-plugin-babel": "~4.5.0",
"#vue/cli-plugin-eslint": "~4.5.0",
"#vue/cli-service": "~4.5.0",
"babel-eslint": "^10.1.0",
"eslint": "^6.7.2",
"eslint-plugin-vue": "^6.2.2",
"vue-template-compiler": "^2.6.11",
"webpack-bundle-tracker": "^1.6.0"
},
"eslintConfig": {
"root": true,
"env": {
"node": true
},
"extends": [
"plugin:vue/essential",
"eslint:recommended"
],
"parserOptions": {
"parser": "babel-eslint"
},
"rules": {
"no-unused-vars": "off"
}
},
"browserslist": [
"> 1%",
"last 2 versions",
"not dead"
]
}
js entrypoint
import Vue from 'vue'
import myapp from './myapp.vue'
import { PiniaVuePlugin,createPinia } from 'pinia'
Vue.use(PiniaVuePlugin)
const pinia = createPinia(); // <-- this is the problem
new Vue({
pinia,
render: (h) => h(myapp)
}).$mount("#myapp");