When my server detected PB global ban and PBBANS cached it, I always report these players at BF4DB.

Global banned player usually has abnormal stats so I think these bans are vaild.

But I found the Global banned player I reported before, can join PB protected server(ranked and PB is ON)

https://bf4db.com/player/1772605535 

It was odd that GLOBAL bans triggered such low level(rank 14 when I reported in March) and skill pretty bad compared with normal cheater

PB Global banned could be lifted and banned player play again in ranked server?

Well a ban can be lifted, but I doubt it has been done in this case if you look at the dates.

The player stats doesnt need to indicate a cheater, PB might have caught him trying to cheat which triggered it before his stats went "funny".

PLAYER NAME: Piromi1003
GUID: d029f104193867752cb35c11ff80cb73
FIRST SEEN: 2018-03-08 06:49:02
LAST SEEN: 2018-03-10 10:47:08
CURRENT BANS: PBGL

Global bans in PBBANS are cached, so they are not updated in real time. The ban could have been lifted which is how he is able to join servers.