http header parse invalid when request multiple url request in one session

[topelinux]

to produce start the ./functional-test-server then

curl -X GET --header "content-type: application/json"  -v   http://127.0.0.1:8080/echo --next --header "content-type: application/json"  -v   http://127.0.0.1:8080/headers

the expected behavior is the receive on client side

Host: 127.0.0.1:8080
User-Agent: curl/8.1.2
Accept: */*
content-type: application/json

the acutul behavior is no response on server side, for the server the url is not valid parsed, added the screenshot for information