I'm having the same issue! so annoying! It does the same thing with "shuffle" too - click to shuffle playist, and 2 mins later it has turned off shuffle by itself. Both of these are extremely annoying, especially as I listen to Spotify whilst driving. Please fix these issues!
Running on iPhone 6S+ - iOS and Spotify both up to date
I am having the same problem. Using an Iphone 6s up to date. Tried reinstalling. A few seconds after I open spotify or when I get into my car and bluetooth activates it, the repeat button goes green by itself. VERY annoying. Please fix this bug or at least give us a way to disable repeat in preferences. Been going on for months.