Cyberpanel inaccessable behind Cloudflare

When the cloudflare firewall is enabled, I am unable to access Cyberpanel.

I have set up a proxy as shown here: How to remove port 8090 from CyberPanel - CyberPanel

Which functions correctly. However the webserver is blocking my access with a 503, claiming a suspicious request, heres the logs:

2019-10-21 22:51:17.080302 [NOTICE] [9369] Suspicious request timeout, associated process: 0, running: 0.
2019-10-21 22:51:17.080365 [NOTICE] [9369] Max retries has been reached, 503!
2019-10-21 22:51:17.080391 [NOTICE] [9369] oops! 503 Service Unavailable