Front camera displaying horizontal black lines or purple bars

My ipad mini 5 suddenly developed a fault which seems to originate from the front camera: in FaceTime or the Photo app either a thin black/green line is visible in the middle of the screen or one or two purple bars usually two thirds up on the screen. Interestingly they do not rotate when I rotate the screen.

The fault is not always present, sometimes it disappears for a day or so and then comes back.

Switching the camera makes the fault disappear, so it definitely is related to the front camera.

Software is up to date, the device is just over a year old and has never been dropped.

Anyone else experienced this?