Use (free) to convert the file.
is an open-source video codec library developed by Google. It is the reference encoder for VP8 and VP9 . superman & lois s04e01 libvpx
If you downloaded Superman & Lois S04E01 and the metadata says Video: VP9 or Encoder: libvpx , you have a or MKV file encoded in Google’s format. Use (free) to convert the file