Samsung is prepping for the Galaxy S8 launch and is buying up every Snapdragon 835 chip in sight. Which causes headaches for other companies as there aren't enough units left and won't be until the S8 launches, claim anonymous industry insiders. It seems even LG didn't have enough pull to secure S835 chipsets for the upcoming LG G6, which will launch ahead of the S8 (and so will the HTC U Ultra, powered by S821). This won't be the first time LG opts for a chip lower on the totem pole, though with the LG G4 it was about the thermal issues of the top chip rather than lack of...
Source: http://www.gsmarena.com/samsung_allegedly_hoards_s835_chips_for_the_galaxy_s8_leaving_nothing_for_lg-news-22941.php