I am having the same original problem. When I attempt to post a new version, as I am building out the pack testing each mod individually - as recommended by many posters on this site, the updated version is simply not available in Technic Launcher. Sometimes it does, but usually no. Maybe I just need to wait a really long time, and the update will finally post?
Out of frustration many times I find the only option is to delete the pack and create a new one. But that locks the original pack name - not great either.
What gives?