Second series of Those Who Kill not recognised by Plex

Can anyone suggest why PMS is not recognising a second season of a Danish series Den som dræber - Fanget af mørket Those Who Kill.
I downloaded both series from BBC iPlayer which identifies the series as Blinded: Those Who Kill and Darkness: Those Who Kill.
On TVDB they are both shown as two seasons of the same series . Season 1 being shown in 2019 and Season 2 in 2021. Also on the programme website which has a different name Den som dræber - Fanget af mørket translated to The One who kills Caught by the Darkness they are similarly shown as two seasons. I have unmatched and matched the folder and maually selected Those who Kill (2019) which appears to bring back the correct poster and background but it only recognises a single series. The files are named as downloaded ie Season 01 Folder “Darkness Those Who Kill S01E01” , “Darkness Those Who Kill S01E02” etc and Season 02 Folder “Blinded Those Who Kill S02E01” , “Blinded Those Who Kill S02E02” etc. The parent folder is named “Those Who Kill”. Is this a problem with the Danish drama not being recognised even though there is an entry in TVDB or is it a naming convention. e.g. should I drop Blinded and Darkness from the file names? Is there any way to search for the IMDB number in PMS when you dont get a proper match?
Many thanks
Fozzie

What’s the full directory structure?

Matching the TVDB show naming (not season) is typically the best bet.

Those Who Kill (2019) {tvdb-235981}/
  Season 01/
    Those Who Kill (2019) - S01E01.ext
    Those Who Kill (2019) - S01E02.ext
  Season 02/
    Those Who Kill (2019) - S02E01.ext
    Those Who Kill (2019) - S02E01.ext

Consider enabling Season Titles in the Library’s Advanced settings.

Thanks Volts,
Structure is as follows. I haven’t dated Parent folder as the Season 1 was 2019 and season 2 2021 and never know if you should include the original broadcast date.
Those Who Kill
Season 01/
Darkness Those Who Kill S01E01
Darkness Those Who Kill S01E02
Season 02/
Blinded Those Who Kill S02E01
Blinded Those Who Kill S02E01

I am wondering if I should drop the prefix Darkness and Blinded fro the file names.

The year is only necessary to resolve conflict when multiple shows have a similar name.

Including the TVDB (as I did in the example) is an excellent way to force a specific match.

Probably. I would guess that’s the confusing factor.

yeah I would make all the prefixes the name of the show. You can add the prefixes as season titles when editing show in UI if using the new “Plex TV Series” agent