Do your logs show the user’s ip addresses or do they show the icloud addresses? If it’s the latter then you need to fix the nginx config so that the end user ip is getting to discourse rather then the proxy. The topics about running discourse with other servers have the code that you need to add to the app.yml to fix that. You need to change the x-forwarded-for, if memory serves.
You can override that setting with an env variable
DISCOURSE_SETTING_NAME: value
I’m not going to try to type it on my phone.