And thank you for providing all the detailed information. You are one of the rare few members who followed the instructions properly. Kudos for that
Now coming to your problem, installed applications usually have a .desktop file in /usr/share/applications directory. This is from where the applications are added in the menu.
Could you please check if Chirp has the desktop file present in this folder?
Please use this command:
find /usr/share/applications -type f -name “chirp*”