Getting jquery related error while trying to upgrade from @rails/webpacker to shakapacker

Question

I tried following the upgrade guide here: https://github.com/shakacode/shakapacker/blob/master/docs/v6_upgrade.md

and the demo project here: https://github.com/shakacode/react_on_rails_demo_ssr_hmr

When I started my app, I get the following errors in the console:

Uncaught Error: History.js Adapter has already been loaded...
    at application.js:32465:9
    at application.js:32522:3
(anonymous) @ application.js:32465
(anonymous) @ application.js:32522
js?key=AIzaSyCh_6b69IBS90SCXX52dIC_wTo0Db-OnMw&v=3&libraries=geometry,places:372          

VM1079 application.js:54568 Uncaught TypeError: $(...).popover is not a function
    at HTMLDocument.<anonymous> (VM1079 application.js:54568:40)
    at fire (VM1079 application.js:3233:31)
    at Object.fireWith [as resolveWith] (VM1079 application.js:3363:7)
    at Function.ready (VM1079 application.js:3583:13)
    at HTMLDocument.completed (VM1079 application.js:3618:10)
(anonymous) @ VM1079 application.js:54568
fire @ VM1079 application.js:3233
fireWith @ VM1079 application.js:3363
ready @ VM1079 application.js:3583
completed @ VM1079 application.js:3618

application_shipper.js:2630 Uncaught TypeError: $(...).documentUpload is not a function
    at HTMLDocument.<anonymous> (application_shipper.js:2630:58)
    at fire (application.js:3233:31)
    at Object.fireWith [as resolveWith] (application.js:3363:7)
    at Function.ready (application.js:3583:13)
    at HTMLDocument.completed (application.js:3618:10)

I also see this in the terminal:

Webpacker::Compiler - Slow setup for development

Prepare JS assets with either:
1. Running `bin/webpacker-dev-server`
2. Set `compile` to false in webpacker.yml and run `bin/webpacker -w`

I have been stuck with this for the last day or so. Can someone help?

Things I have tried:

1. Confirm bin/webpack-dev-server starts up fine
2. confirm bin/webpack -w is fine
3. yarn install runs fine
4. I have tried downgrading to shakapacker 6.0.0
5. Upon googling around, this seems like jquery error to me so i tried instructions here: https://github.com/shakacode/shakapacker/blob/master/README.md#webpack-configuration but that didn't help much too.
6. I'm using Node 12 but tried upgrading to Node 16 (16.17.0) but that doesnt help either

Can anyone help?