Parrot Sequoia RGB purple images

Hi, I’ve been using a Parrot Sequoia camera for a long time on a drone built by a university, but this problem can only be found on my vehicle and not on others already sold. The first year of flights with the Parrot Sequoia camera went very well without any problems.
In this season however, in some images of the RGB sensor I found artifacts of purple color. If they then merge the RGB images, reconstructing the orthophotos map, the artifacts seem to merge into bounded spots.
Can you give me the cause of the problem?