Android App no longer keeps my login info after powering device off

[aunit0]

I've had my Android Car Stereo for about 9 months and kept my free spotify account on it.

Starting last week, my login is no longer saved when I reboot the device.

My friend used his premium account on it instead and it will keep the login info even after a reboot.

Is there any way to resolve this? I don't see why a stored login should no longer be available for a free version of an account.