Help PUBG folder

[From nowhere]

I just re-installed steam before I do that I back-up whole steamapps then I copied it to new steam folder. But steam asks me to download PUBG again start from 50% 3.6GB, steam can recognise my other games such as dota 2 and no need to download anything. I check size of PUBG folder in steamapps/common, it's only 1.4KB no game files at all. I check another folder downloading, there is a folder name 578080 contain 7.03GB and somehow PUBG files in there. What should I do?