Is the rear camera glass needed for focus?

I cracked the rear camera glass on my S8, and am waiting for the replacement to get here. I removed the broken glass and adhesive, did my best to make sure that no dust or shards of glass are caught up in the camera assembly, and checked to see that the camera still works. I then covered it up with a piece of paper and some tape to keep any more dust out.

I needed to take a picture today, and noticed that it won’t focus on anything closer than about 6 inces. Focusing on further subjects works just fine. Could this be a symptom of not having the small glass cover over the camera, or do I have a bigger problem on my hands?