Randomly adding songs from one playlist to another

[Skeeter34]

Plan

Premium

Country

USA

Device

Google Pixel

Operating System

Windows 10

My Question or Issue

So I have multiple playlists for different genres and lately I have noticed that songs from one playlist (rock) are seemingly at random being added to my other playlist  (rap) when I switch back. On top of that older songs that have been in the rap playlist for years are getting readded so they appear back at the top of the playlist when sorted by date added. This incredibly frustrating and I would love any help.