If Picons/Channel Logo’s are not updating when changed do the following to clear the logo cache in kodi.
rm $HOME/.kodi/userdata/Thumbnails/*/*.png
rm $HOME/.kodi/userdata/Database/Textures13.dB
The above assumes a Linux based OS. Alter the command for other platforms.
Then restart kodi. Note that your Textures*.db file may have a different number.