dmgadagio

If you decide to do sensor cleaning, I suggest using a blower first to remove loose dust. I recommend the ORBIT HEPA Blower for its HEPA filter

The issue seems on the surface, but is not functional. I recommend using the Sensor Swab kit, which should remove the lens cleaner residue completely, especially since you described it as just a visible smudge and not etching or damage

If your sensor still has dust spots after automatic cleaning, I highly recommend using the Sensor Swab kit by Photographic Solutions. It’s one of the most trusted tools for safely and effectively removing stubborn dust and smudges from your sensor

Use the 17mm swab size of Photographic Solutions Sensor Swabs. Thats the one that I use on my XT-20. Try it!