Is this the ShootingSight EBR trigger?
Is the disconnector adjusted correctly so that you have a second stage, and the trigger cycles as it should? The safety does 2 things: it latches over the front edge of the hammer, but it also has a step that cams in front of the trigger sear to prevent the trigger from being pulled. If your trigger is not in the full forward position, you cannot engage the safety.
So this makes me think somehow the trigger has not reset properly, which can happen if the adjustment on the disconnector is mis-set.