Plex Series agent keeps matching me to the wrong for for this one title

Difficulties to match that series are to be expected, considering that they both aired in the same year, and their titles only differ in the second half.

Plex has a mechanism for this kind of situation.

/TV Shows
   / Grand Maison Tokyo (2019)  - {tmdb-95718}
      /Season 01
         Grand Maison Tokyo - s01e01 - Red Shrimp Étouffée.mp4
         ...

Keep the agent of the library at “Plex Series”. Don’t change it willy-nilly, it won’t do any good.
Rename your folders like above, then perform the Plex Dance with the whole show.