Same happened with my s23 phone. Today afternoon one faint white line started visible on display. After March update number of customers have reported this. Talked with support they told me to visit service centre with original bill

Tuesday ja raha service centre.Chat support has told me that if the phone is under 3 years with original bill then they will replace the display

See

Same happened with my s23 after update. A fades white line has appeared on my phone left side of the hole punch