Canon R3 Purple Circle on new R3 Photos?

[mtpg1]

Hi, I recently got a R3 and a canon 100-500 lens and the first proper outing shooting military Aircraft resulted in some shots having a sometimes very faint and sometimes more prominent purple circle usually slap bang in the middle of the photo. Has anyone any idea what could be causing this, Ive posted a photo as an example.

 

[Only RF]

Is the R3 brand new? it does not look like a card issue but you never know. Have you tried a different card?

 

[mtpg1]

Is the R3 brand new? it does not look like a card issue but you never know. Have you tried a different card?

yeah it's only two weeks old, haven't tried another card but cant see it being the card as 99% shots are fine