ntozier Hi and thanks for the reply.
I was unable to see OsTicket work with PHP 7.4 so moved to another system.
Sometimes in my test from a new install, generated by the Softaculous installer, the system when captcha is not inserted never give errors but loose all ticket text: once a send button is pressed simply it returns to the OsTicket home page where check existent ticket or open new one and is impossible to recover the not sent ticket.
I suggest to try to send some ticket without captcha.
Umh I tested now with an on-line demo but I'm unable to reproduce the issue.
Maybe some custom settings I used to translated field.
Thanks again for the reply.