RT!
There may be a Property Handler shell extension installed which offers to save the tags, but then does nothing while still returning success. We've seen that with some formats and components of video software.
Opus will ask any installed Property Handlers if they can save tags themselves before falling back on its generic method of storing the tags into NTFS ADS.
If your F drive is a non-Windows network share then that's another reason it may fail, since NTFS ADS probably are not supported on the drive but would be the only way Opus itself knows how to associate tags with a .m2ts file.