15 pro max smells like sharpies

Hello~ You need to stop using that iPhone and don’t charge it. It may be that the battery is not functioning properly and expanding. Click on below and have it checked out sooner than later….

Genius Bar Reservation and Apple Support Options - Apple

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~Katana-San~

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iPhone Repair and Service - Apple Support

Hey, I have the exact same problem as you since yesterday, now I'm starting to cough... (I have the same iPhone as you.)

The advice posted by the two knowledgeable folks above would be relevant to your issue as well.

Totally, I put it in another room because it smells so strong...