Sam

The list of plugins is in my previous reply.

WooCommerce
Printify Shipping Method
Cloudflare Flexible SSL

I can’t say for sure, I assumed all.

Yes, as if the plugin were disabled.

WP version: 5.4.2
Custom theme

The environment is essentially this: https://github.com/PhilippHeuer/wordpress-heroku

I just got this error after enabling guest voting, logging out, and loading the page.

Hi Emre. I stopped trying with this as I found I could get good results by optimising before uploading the files. So no URL to share I’m afraid.

Thanks for the tip LiamE.