Agreed. I bought my Canon RP used and discovered about 6 of these, quite by accident. Turned on the camera with the lens cap on to see the battery level and saw a bunch of "stars" that shouldn't be there. Some where white, a few blue, and one red. It took at least 6 sensor cleanings to unstick them and the red one hung on the longest.
If I remember correctly, the trick is to go into the menu, trigger a sensor cleaning and turn off the camera once it starts, then turn it back on. In most cases, just running the sensor cleaning did the job. But, for the last one, I had to start the cleaning then suddenly turn off the camera then turn it back on. It took several tries but it worked and the problem hasn't repeated.