TVHeadend Imports the EPG Data from e.g. epg.xml over tv_grab_wg nicely for the first time, but it dont updated it. Its because the e.g. epg.xml file is mounted as Docker Volume to give TVHeadend access to it.
The Problem is Docker does only see the File as “new” when it changes completly or created new. If the epg.xml File is updated and the Inodes change, Docker does not update the mounted File so in the Container i have always the first imported epg.xml but not the last updated one.
It works now, the Trick is to Mount the Volume to the EPG Folder not to the EPG.xml directly. If its mounted to the EPG.xml directly in Docker and the Inode changes Docker want recognize this so it want be updated. Its more a Docker Problem then a TVHeadend.