Many thanks for your feedback!
I've just released Mp3tag v3.29a which introduces an option for video-specific mappings for Matroska video via Options → Tags → Advanced.
This is to increase compatibility with apps that, e.g., only read TITLE with target type T=30.
@BlackFirePhenex, if you disable this option, Mp3tag should write TITLE as in v3.28 so that VLC and any other app that requires the track-level target-types can read and display the title.