Sorry for the issue, can you please confirm if this is still the case as Cloudflare had a network issue recently which is now resolved. Also, what is your reason for saying that it is ‘ALL websites’ in the Netherlands?
If it is still not resolved, here is some information about the errors:
A 520 error occurs when the connection started on the origin web server, but that the request was not completed. The most common reason why this would occur is that either a program, cron job, or resource is taking up more resources than it should causing the server not to be able to respond to all requests properly.
Review the Quick Fix Ideas in this Community Tip for troubleshooting suggestions.
A 522 error typically happens when Cloudflare requests to the origin (your webserver) get blocked. Review the suggestions in this Community Tip for troubleshooting ideas.