Be cautious when visiting sites included in filenames (like the one mentioned). Always use an ad-blocker and updated antivirus software, as these sites are often heavy on intrusive ads.
This is a watermark or tag from the website where the file was originally hosted. Bula20221080pVMAXWEB-DLTheMoviesflixnetmkv
Use VLC Media Player or MPC-HC . These players handle .mkv files and various subtitle formats easily. Be cautious when visiting sites included in filenames
File names like this are "scene tags" that tell you exactly what you are getting: The resolution (Full HD). Bula20221080pVMAXWEB-DLTheMoviesflixnetmkv
Likely the "release group" or the specific source/encoding team.