Samsung phone still bricked via FRP after factory reset
Be sure that the stock firmware is correct. It should be 1 or a few gigabyte(s) in size.

I've finally unrooted my phone. I used Updato's firmwares (which is the only one that has SM-J111F stock firmwares), specifically SM-J111F with product code XME and its PDA as J111FXXU0AQD2 (J111FXXU0AQD2_J111FOLB0APL2_J111FXXU0AQC2_HOME.tar.md5).