Access Error: Request Entity Too Large HTTP Header Field exceeds Supported Size

What is the name of the domain?

hoang-hiep.com

What is the error number?

413

What is the error message?

Access Error: Request Entity Too Large HTTP Header Field exceeds Supported Size

What is the issue you’re encountering

I installed Cloudflare on my home PC and set up a public hostname using the Tunnel service for my Cisco switch. For example, cisco.hoang-hiep.com maps to 192.168.88.1. I can log in successfully through the tunnel, but when I try to access the Cisco switch, an error occurs. But Other devices, such as my router and self-hosted DNS, work perfectly.

What are the steps to reproduce the issue?

everytimes I access to cisco.

Screenshot of the error

How large are the headers? The limit is 16KB per header and 32KB total.