LG's devices have a history of experiencing bootloops at some point for a seemingly unknown reason. More specifically, many customers had experienced bootloops on the LG G4 for an unfamiliar cause that LG was misdiagnosing at the time. It took the Korean Smartphone maker a while before it released an official statement regarding the cause and resolution of the bootloops. LG said the cause to blame with a hardware issue, where "a loose contact between components" needed to be repaired. Thankfully, LG was committed to fixing the problem, and arranged to repair customers'...
Source: http://www.gsmarena.com/lg_blames_cheap_usb_typec_cables_as_cause_of_bootloops_on_the_v20-news-22252.php