If i pull the power cable out after a few minutes it goes away but returns as soon as i connect again......have you took the power cord out? pull it out and check.
A power led coming through?
Are you sure that its a different monitor? Did you take note of the old monitor's serial number before sending it back? If its not noticeable when the monitor is on they may not class it as a fault. If it makes no difference in windows or playing games I'm not sure I'd be worried about it either tbh.
Isn't that just the bezel pressing too firmly on the panel which causes the glow?
No, you're right. I wouldn't be happy with it. It actually looks worse than the last one?