After 1-2min of my first song, my iPhone 6S will do a re-start. This re-start is little weird as there won't be any apple logo, But a black screen with loading circle for 5-7sec and lock screen will come up. I can use my fingerprint scan to unlock. Usually, when iPhone restarts fingerprint will be disabled and we need to enter the passcode to unlock. Once I am in all my apps will be minimized (like, Spotify stops playing songs. And if maps are on, it will stop completely and I need to enter my destination again and start navigation). this whole re-start will be done in less than 10-15sec.
This weird behavior won't come back at least couple of hours after the first restart. I can use the Spotify app and my phone without any problem after the first restart.
I am dealing with this issue at least couple of months now.
I tried re-installing app as in different ways mentioned in the support forms
contacted apple support regarding this, as per their suggestion instead of doing a backup restore I did a new phone setup and installed everything again.
Still this problem not resolved.
iPhone 6S 64GB (MKRG2LL/A)
iOS Verison: 10.2.1 (14D27)
Spotify Version: 18.104.22.1680
Spotify Premium user
[Edit 1] See video in below link, you can clearly see in the video what I am explaining above.