contextual filter & main image not always displaying

I display a view with a contextual filter (nid) which worked beautifully in the previous version. The multi-field image is displayed using Gallery Formatter. I've upgraded on localhost and found that the 1st attempt at displaying the view after a cleared cache results in the main image not being displayed. Usually, the 2nd attempt at the same node results in the main image being displayed but not always. Sometimes it requires several attempts.