iMac M1 2021 hot upper lever corner and lines.

Unfortunately you're not alone. The following topics illustrate the Silicon M1 iMac Display problem:

Screen Failure on 24-inch-iMac, M1, 2021 - Apple Communit

Persistent horizontal lines appear on iMac Screen - Apple Community

Horizontal Lines on Screen of iMac, 24", 2021

Horizontal black lines covering bottom 3rd of 2021 M1 iMac screen

Grey horizontal patches on my M1 iMac 2021 model

Horizontal lines at the bottom of iMac(M1,2021) screen

Do what's been suggested and let Appe know about the screen problem. As the saying goes: "The squeaky wheel gets the grease". Let them know via iMac Feedback.

Javier,

Rather than ranting about what Apple "should do" please send them feedback at www.apple.com/feedback. We understand and are empathetic but ranting here does not help and violates the Terms of Use.

By the way, Apple does not read or participate in user to user forums so let them know how you feel on the appropriate place.

Same problem. iMac m1 24” 2021, The screen has horizontal lines that have come out of nowhere. I am seeing that this is a very common occurrence with this model seeing the same complaints from many users. The computer has been taken care of and in normal use. Apple should do something about this.

Have you considered making an appointment and taking it in for service?