https://www.bleepingcomputer.com/news/apple/apple-pulls-ipados-18-update-bricking-m4-ipad-pro-devices/

Apple has paused the rollout of iPadOS 18 on iPad Pro tablets with the M4 chip after numerous owners reported the update is "bricking" their devices, with no way to turn them on after performing the update.

Attempts to overcome the problem using standard recovery methods such as force restart or entering recovery mode have not worked, leaving impacted users with no choice but to visit an Apple store for evaluation.