Whenever i try to copy files from the phone to usb or vice versa to a usb using an OTG cable, it either takes a long to detect the usb or after detected the data transfer speeds are so slow. It shows 6hrs for transferring 1gb of file and it is super slow and yes it is the same case for every usb and every cables ive tried. Whereas when i use these same cable in a really old device i have it just tranfers the data within 2-3 min.... and that phone is 4-5 years old... Honor 9n if u were wondering... but i bought iqoo z5 this may and it cant even transfer files? im pretty sure lots of peoples are facing this issue. It could be the software. So i would please request you guyz to see if this porblem persists on other iqoo z5 devices or it could be a bug on the software... 

Thanks.

PS: i am 99% satisfied with every thing this phone has to offer other than this problem.