Hi @j22kj22k 

This songs with purple dot was added to playlist from Deezer song editor and is new there and playlist is updated . When you open playlist you can see songs which was last added there .

After you see them and go out of playlist then purple dots will be disappear .

I’ve played the song, and refreshed the page. There is no change. - Plus, these songs are not newly added.

For example  Deezer editor added songs 3 weeks ago , and you did not open the playlist.
If you were to open a playlist today, there are marked songs with purple dots because they are newly added and you didn't see them. 
The purple dots will disapeare after some time . 

One of the songs was added in 2022, as shown in the screenshot - I have definitely opened the playlist since then.
I made sure that date was not the date added to Deezer. That single came out a month prior to the added date.

@Leonídia.Deezer  Bug?

Video attached.

To clarify - playing the song, then going into another play list and then going back showed the song as “New”
Clicking into the album seemed to make it “played”
Refreshing the page made it “New” again.

Same playlist - different browsers