Not sure if this is related, but my login problems stopped after disabling lightdm, installing gdm and enabling gdm.
Before doing so, on 64 bit Antergos, I would not be able to log in after a the screen lock triggered. On 32 bit, the screen would go white after screen locking and I would not even see a login screen. Maybe the new install isos improve this. I just stopped using lightdm instead of re-installing.