Diffraction spikes

[Dave_D]

Noticed this on a few of my pics. Bright stars are showing more than 4 diffraction spikes (4 vane spider). is the cause of this possibly because opposite vanes on the secondary arent perfectly lined up? i just had a look with a steel rule and there appears to be a millimetre or more gap between opposing vanes. 

[Moonshane]

your suggestion is most likely but your focus looks off too.

[Dave_D]

it's a highly enlarged section of the sub and showing a bit of trailing because it's unguided. focus was good according to my bahtinov and 10x liveview but hey, who knows