House Training a Year Old Dog?

My year old neutered male Shih Tzu comes to me after he pees and shows me where he actually went. He gets walks daily, has regular and multiple outside times to relieve himself that are for this purpose only, seperate from playtime outdoors. It is as though he has it "backwards", I am not sure how to reverse this behavior.

He will oftentimes go to the door or come look at me with that signal look, but daily there are the "other" times. He has access to me all day, in a studio apartment. There have been no changes in lifestyle to attribute this to. These indoor accidents are lessening, 2 a day now, no more at night. I have tried a tastier reward upon re-entering the house each time after a successful potty, to no avail.