Same issue here. I own a X-T2 and the turn off-turn on message appeared out of the blue this afternoon when zomming in past 27 mm. I can still take pictures when zoomed completely out (18 mm), but when I zoom in, the message appears. Have been using this lens for over two months. Cleaned the contacts with isopropyl alcohol, but no luck. I immediately bought an identical second hand lens for € 280, but still am very curious on the issue and a possible remedy ...