Thank you for the responses, I'm afraid it turned out to be a problem with inexperience with Kodi. I've now got it working as expected.
But when adjusting settings in Kodi, it seems that different pages behave differently when it comes to when the changes are saved. Also sometimes there seems to be a considerable lag between when you press a button (I've been using Kore) and the interface presents you with the options, so that an inexperienced user might think that it was dead button and moved on to explore what other ways there are to achieve the changes he wants.