Hello, We would like to apologize for the experiance that you're going through, but please clarify more about the major function issue that you're facing with your Z fold device, so that we can help further.
The phone is constantly lagging ,with the brightness increasing to a maximum and the phone heats up and it stays like this for hours , most times the phone will not accept or make any calls.
For assistance, please visit one of our authorized Service Centers to check it for you. You may refer to the link it will guide you to the nearest service center to your location https://www.samsung.com/ae/support/service-center/
