Data Saver mode does not turn off

[Hwest9072]

Plan

Free

Country

Republic of korea 

Device

Samsung Galaxy S8+

Operating System

Android Oreo

My Question or Issue

Hello.

Even if I turn off Data Saver mode in the setting menu, but it will turn back on when I scroll down and then up to change my streaming music quality.

So Data Saver mode is always on and the streaming music quality is fixed to low.

I can't turn off it.

Please helps.