If you're having issues running cron at all, Cloudflare recommends moving cron to a different subdomain
and/or that you create a new subdomain that we don't proxy.
Options:

1. Run your cron jobs under your direct subdomain (direct.example.com).

2. Create a subdomain for cron, then add it in Cloudflare's DNS app and make sure the cloud icon in
    your status field is grey.