Steps to reproduce:

1. Create a HTTP agent item; uncheck "Follow redirects", put "302" as value for "Required status codes"
2. Use the "Test" button: it works; the returned value is the 302 response with its headers and everything
3. Click "Add" to create the item

Result:

Redirects are followed. The item goes unsupported with error message 'Response code "200" did not match any of the required status codes "302"'.

If the "Required status codes" is changed to "302,200", it does work and the item value is the expected 302 response (so not the final response after following the redirect).

Opening the item configuration again, shows that "Follow redirects" is checked again.{}

Expected:
**

The checked/unchecked state of the "Follow redirects" should match what is configured for the item, not be hardcoded to checked.

Extra remarks:

I tested this on 6.4.6 and the buggy behaviour was there. On Zabbix version 6.0 the expected behaviour is observed.