I had a similar problem with an Olympus Mju-II. I saw such ring-shaped flare in night shots, with light sources in the field of view. In your case, I bet you were shooting into the sun, something I generally avoid. And when the sun is close to the edge of the field of view, I shade the lens with my hand or that of a helpful family member. And, my second Mju-II does not have the problem. Possibly someone at Olympus forgot to paint black some lens edges.
You might consider the optical and practical (weather-proof) qualities of that camera before you confine it to expired film.