I think there is still an outstanding issue of 1080i settings not sticking. I’m not sure when those fixes will be made. If that’s the case, I believe the default is a bob-deinterlace to 1080p, which looks bad and prevents your display from deinterlacing it.
As for the reported resolution, the OSSC reports line counts, not video modes; so, when you see 1125i, that is what you know as 1080i, because there are 1125 lines total per frame, 1080 of which are visible. 960i, from what I’ve been told, isn’t a thing.