修改站点和主页URL后无法访问WordPress站点

First of all the technical details:

OrangePi Zero (512Mb)
Debian for Orange Pi
Apache2
PHP5
MYSQL
Wordpress

I have at home an OrangePi and I installed a WordPress on it. I registered a DNS name (exlample.ddns.net) on noip.com.

I used the following guide to the installation:

https://projects.raspberrypi.org/en/projects/lamp-web-server-with-wordpress

After the installation, the blog site is at home reachable and manageable, but from outside can't reachable (It try reach my private address): So I modified the site & home URL in WordPress settings. After that I can reach the site from outside with the DNS name properly, but I cannot reach the blog site from home (only from outside).

Do you have any idea for this issue?

Thank you in advance!

The problem has been resolved. I added the DNS name and the IP-Address of the Server to the host file of my PC. So I can reach my website from the outside and from my private LAN also.