I haven't looked into these too much but weren't some of the infrared ones explained as reflections within the optical system? The sun is a pretty bright source of light, with lots of radiance in the infrared... you can only prevent so many interreflections within an optical system with coatings - the sun (or its reflection) can get though at some angles and the tracking algorithms makes the optical system adjust to keep the artifact relatively stable.

Publishing these as 'unidentified' might be a good way to putyour own branch into the news cycle and acquire more money through political channels. Also, keeping enough of the environment/state in which the phenomena occured classified prevents any foreign actors from precisely identifiying weaknesses in the systems in use.