The problem

Every operation in the web gui results in a warning message, that the POST data sent by the device itself is wrong.

Which version of ESPHome has the issue?

2024.12.2

What type of installation are you using?

Home Assistant Add-on

Which version of Home Assistant has the issue?

No response

What platform are you using?

ESP32-IDF

Board

ESP32-S3 SuperMini

Component causing the issue

web_server

YAML Config

web_server:
  port: 80
  ota: false
  version: 3

Anything in the logs that might be useful for us?

[W]
[web_server_idf:070]�[1;31m[httpd]�[0;33m
Only application/x-www-form-urlencoded supported for POST request

Additional information

The request sent is indeed text/plan, not application/x-www-form-urlencoded:

Hypertext Transfer Protocol
POST /light/metro_display/turn_on?brightness=95 HTTP/1.1\r\n
Host: 192.168.2.81\r\n
Connection: keep-alive\r\n
Content-Length: 4\r\n
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36\r\n
DNT: 1\r\n
Content-Type: text/plain;charset=UTF-8\r\n
Accept: /\r\n