Horizontal white line flashing across iPhone 13 promax screen

Make an appointment to have your phone examined at your local Apple Store:

Genius Bar Reservation and Apple Support Options - Apple

No one’s trying to rip you off.

If it’s intermittent it’s hard to diagnose.

You said it’s now continuous which means it should be easy to show any Apple servicer.

If you show it to Best Buy, they can document the issue (so it’s not just your word it’s occurring) and though they may not work on the 13 Pro Max directly as an Apple service provider they can arrange for the work to be done.

I have this issue also. I spent hours online with Apple Support and finally went through all the hassle of sending the phone in to tech. Of course they said nothing was wrong with it. A couple of weeks after getting it back, setting it up again, the white line of light is back and is there continuously. We do not have an Apple Store close to us. Was advised by Apple to take it to a local Best Buy. Once there they told me Apple does not allow them to touch the iPhone13 Pro Max...

I do not think it is unreasonable to demand a new phone that actually has no defects. I so hate being ripped off!!

It was continuous from the time I first turned it on towhen I sent it in, but I have no idea what it looked like when it actually arrived at the Apple center.

It's all just so frustrating, time consuming and disappointing. Then to be told there is no problem when there clearly is.

I have read remarks from others about lines of light appearing, but see no answers on how to resolve the issue.

Thanks for the suggestion. I will try to get over to the city with Best Buy soon to ask them to document the issue.

I get it, I’ve definitely been on both sides of that fence, trying to get something clearly broken fixed and trying to diagnose something that just won’t misbehave for me.