When doing a commit of a large subfolder's files (~1000), the commit action dialog stops, showing the log with the huge command-line of filenames that is many pages long... and it is not obvious that it failed unless you scroll down to the bottom of the many pages and see the "commit failed with errors.... see above". However, there is no errors that I can find, so I cannot tell you why it failed.
I then performed the commit of the same files usinig TortoiseGit and it worked fine.
I could go back to a different branch that still contains those files, and retry the commit, if you want me to gather some other info.