Can't add song to other playlists

[Lisachloe]

Plan

Premium

Country

Netherlands

Device

Samsing S23 

Operating System

Android

My Question or Issue

When I want to add a song to my playlist (not shared or collaborated playlist), the song does not appear. When I go back and try again, it says that the song is in this playlist but it does not show. When I add it to liked songs it adds it to that playlist. The issue is adding it to other playlists. Can someone help me out?