Check your Windows update history, the updates will say what version the updates are for, 1703 or 1709.
Try and remember to make a note of when it happens, evenings, weekends etc.And no theres no pattern i can discern, it comes and goes for hours or even days at a time
Week off work with feet up helping out on forums likewise I hope that you are enjoying the holidays as wellAlso hope you had a good Christmas