verticle Stripes in my pictures

[peter11002]

Hi,
from time to time I find vertical stripes in the pics of my 11002m as shown in the appendix? (I don't mean the colum error)

I selected a temperatur of -20°C (Outside temperature was -10°C) and all pictures are showing in the fits header a actual temperature of exactly -20.00000°C.
Is this possible?
Or might it be, that the cooler failed but the camera shows  credible values?

I'm using MaxIm DL 6.13 and control my 11002  via ASCOM 6.13.2 - ATIK Camera2 and the 11002 driver 6.2.2.20532

Maybe someone hs an idea.

CS (with working cameras  )
Peter