I do not know why your country coordinator did not choose to announce its /16 or any parts of it. Perhaps it costs too much, or no ISP was willing to do so. You would have to ask him.
The encap routing table entry for your address is 44.142.0.0/16 141.75.245.225 and 141.75.245.225 is pingable from the AMPRGW router at UCSD.
However, NO addresses on the 44.142.162.x subnet are in the allowed filter list at AMPRGW, so there will be NO connectivity to your DHCP address from the Internet via AMPRGW. Thus the traceroute you show is correctly reflecting your unreachability. You will have to ask your coordinator or your hamnet manager why this is so.
It may be that the next hop in the path out from your hamnet address is a router with knowledge of the tunnels and reachability of the rest of AMPRNet. Again, you will have to ask your hamnet manager how this is configured.
Best wishes. - Brian