Looks like Cloudflare is interfering with your Discourse. I suggest you disable the Cloudflare proxy for your domain (grey cloud icon instead of orange on Cloudflare) or at least disable the protections which are causing the issues.
Looks like Cloudflare is interfering with your Discourse. I suggest you disable the Cloudflare proxy for your domain (grey cloud icon instead of orange on Cloudflare) or at least disable the protections which are causing the issues.