Data Short Life in REST service  #3

Hello,

First of all, thanks for your tutorials. They are very good and useful. I have been following your tutorial #5, and i noticed few things:

1.- If I include the header in the CURL command (-H "Content-Type:application/json" ) like you suggested, the post command doesn't work for me curl. However, if i dont include it, It works.
2.- The life of the data in the REST service at rest.learncode.academy doesn't last even 1 min. Anything that i post on the REST, it is wipe out after few seconds.

Could you tell me what I am doing wrong?

Thanks in advance

Regards
JuanMa