Chrome flue the culprit?

[AMcD]

I have had the X shaped artefacts shown in the very roughly processed image below appear in my images from recent imaging sessions.  All the affected images were taken towards the West.  At the western side of the observatory stands a chrome flue attached to a hot tub.  Could reflections from the chrome be the culprit?  The artefacts do not appear in images taken to the South.