I use clouldflare as a proxy for my public webservers and found out the proxy is hostile to Tor traffic but ONLY without the Tor Browser User Agent.

When proxying any other app through tor (i.e. orbot + amethyst) I would get 403 timeouts. When querying the same page with the official Tor Browser, everything was fine.

Fortunately there's a solution: I created a custom cloudflare WAF firewall rule to allow all tor traffic unconditionally. Seems to work!