Inserting clips in the wrong place on the timeline

I'm running Resolve 18.1.1 and all is well until I attempt to insert a clip or a still image into the timeline. Instead of inserting at the point of the play head, Resolve inserts it right at the beginning of the timeline.
Has anyone else had this problem?

you have set an iN point

Thanks Mark. I also notice that, when I copy and paste a clip, Resolve inserts the copy at the beginning of the timeline even though I have set an in point.
It's probably something in the preferences but I don't know where to look.