Just received an express replacement from Apple for my iPhone 15 PM and had to install iOS 26.1. I then restored from an iCloud backup. Fast forward a few weeks, I’ve noticed my phone randomly reboots (screen goes black with the silver wheel turning for maybe 3-4 seconds) after I unlock my phone. It’s happened 4-5 times since I’ve received the replacement. Is this a software issue or hardware issue? TIA