Any ideas about an iPhone 11 suddenly shutting off until airplane mode and volume buttons are used?

Hey Cregane,

There are quite a few potential causes for a device to unexpectedly shutdown. You mentioned that it'll shut down until Airplane Mode is used. How are you enabling that if the iPhone isn't powering on? Just trying to get a clearer picture of exactly what is occurring here. Also, when you talked about the volume buttons, are you talking about doing a forced restart, or simply tapping the buttons to turn the volume up or down?

You may also be talking about cellular or Wi-Fi signal instead of power, so if that's what you mean, give a few details on that. If this is the issue, how often are you seeing it, and does it always happen in the same place or can it occur completely randomly? The iPhone 11 can run the latest version of iOS, so if it currently isn't that'd be a great first step to ensure it is working as optimally as it can. Here's how to ensure you're running the latest version of iOS

"Update your iPhone or iPad wirelessly

• Back up your device using iCloud or your computer.
• Plug your device into power and connect to the internet with Wi-Fi.
• Go to Settings > General, then tap Software Update.
• If you see more than one software update option available, choose the one that you want to install.

• Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do."

This info came from Update your iPhone or iPad - Apple Support

Take care.