App keeps playing the next song from a different playlist

[Sweepya]

Plan

Premium

Country

USA

Device

iPhone X, PC (Windows)

Operating System

iOS 12 (up-to-date), Windows 10 (up-to-date)

My Question or Issue

As I play songs from other playlists such as Discover Weekly, the next song immediately reverts to another heavily-used playlist of mine. Essentially, I can listen to a song and then I have to physically select the next song in that playlist to keep it going, otherwise it will play from another list.

Curiously, when I look at the little speaker symbol next to the playlist being played, it stays on the playlist I want to listen to, as if it thinks I'm listening to it. Yet is playing songs from another list.