Not sure if this was discussed on this thread or not, i didn't search, but it seems that the --check command doesn't report accurately the builds issued by steamCMD. I am not a coder/programmer but looking at the updateengine.sh script the --check seems to generate a file called 7dtd.appinfo in the /tmp/ directory. From that point on it just continues to look at this file it seems. If you delete file/tmp/7dtd.appinfo and then do a --check command again it seems to see the correct information. However I still had to run the --force to get it to update the server.
Just thought I would post this for FYI. If its a know issue or not an issue then I apologize for the post in advance. =)
Grampy