jRespond not defined

Hello,
I'm installing the JS via webpack (in a Rails 6 app).

I'm currently getting the following error in the console:

Uncaught ReferenceError: jRespond is not defined
    defaults functions.js:242
    init functions.js:86
    init functions.js:2021

here is my application.js file.

require("@rails/ujs").start()
require("turbolinks").start()
require("@rails/activestorage").start()
require("channels")
require("jquery")
require("bootstrap")

require("js/plugins.min")
require("js/functions")

I have installed jrespond via yarn, but that hasn't helped.

Thanks!

It also seems to have trouble loading jsLinking and FlexSlider

Uncaught TypeError: $ is not a function
    anonymous application-be011369c8caa8bf9107.js line 366 > Function:3
    jsLinking functions.js:157
    functions functions.js:220
    loadFlexSlider functions.js:1420
    init functions.js:2159
    jQuery 8
    js functions.js:2240
    js functions.js:2252
    js application-be011369c8caa8bf9107.js:2431
    Webpack 5
application-be011369c8caa8bf9107.js line 366 > Function:3:8
    anonymous application-be011369c8caa8bf9107.js line 366 > Function:3
    jsLinking functions.js:157
    functions functions.js:220
    loadFlexSlider functions.js:1420
    init functions.js:2159