Sometimes a "gap" can be in fact a paper-coloured borderless object which is sitting on top of the border and obscuring part of it. Click on or near the gap, and see if anything reveals itself by displaying its "handles".
Xiaomi Mi Mix 2 review
See mcbess's iconic style animated for Mercedes-Benz
iPhone X news: Release date, price, new features & specs
Black Friday 2017 : date, sites participants & bonnes affaires