I have several of those cameras. They are prone to strange reflections on the dome. First picture is one sitting on my desk and I snapped a picture from it looking up at the wall in my man cave, with a big window right below it. You can see the strange looking spots or artifacts showing up. This camera is perfectly clean, just taken out of the box last week, never been outside or opened up.
Second picture is another identical camera, mounted in my mancave, looking out a thermopane window at my Big Hikvision PTZ. In lower light scenarios, it gets a bit fuzzy and will have artifacts in the picture.
View attachment 133672
View attachment 133673