Always when I wanna rewind the track I am playing right now I have to unlock my phone and do it right into the SoundCloud client.
I don't have the rewind button on my lock screen anymore, which I used to have to push and the song started from the beginning again.
The first time when I had this issue was when I last updated my mobile. I already de- and reinstalled SoundCloud.
I do have an Huawei Mate 10 lite on Android version 8.0.0
(Sorry for bad English, I'm German.)