Moving this thread to General Hardware. Hopefully it won't stick again but there are some software programs you can run which may or may not get rid of a stuck pixel. 
 
Some manufacturers won't accept a return for one stuck pixel unless you have a zero stuck pixel policy on your monitor. 

Its either red or green, happens at different times, it's coming back within a few hours.  There seems to be some pressure from the monitors housing and a twist in the panels sub layers itself causing this.
 
This is 1 of three Asus PG278QR's that have had this same problem, this is the 2nd replacement which is going back to amazon tomorrow to be replaced ONE more time before I give up and go Acer.
 
Is asus really that terrible at QC these days?  This one specifically had a " qc passed. " sticker on it when the others did not!

 
If you can still take it back, you should. Even if there is a policy that say's they won't honor a warranty for 1 stuck pixel. Just tell them you don't like it, or don't want it. As long as there is no physical damage, you should be fine. I also suggest you look into a Samsung or LG monitor. I've had this 27" LG monitor for about 6 or 7 years now, and it still works, and looks as good as the day I bought it. Never had a pixel problem.

 
Return it then.