Apple Watch locked when restarting after long powered-down state I've kept my Series 5 Apple Watch switched off for a long time and restarted it today. It shows &quot;Device Locked. Unlock iPhone to start using Apple Watch&quot; message when I wear it.
On my iPhone 7, the Watch app seems to have forgotten my Watch and shows the 'Start Pairing' screen, but when I go to start pairing mode, it doesn't detect the Watch, and the watch doesn't respond either. The watch is not listed when I go to manual mode as well.
What troubleshoot tips should I try?
To troubleshoot, I would follow the restore steps:

https://support.apple.com/en-us/HT204505

It mentions that bluetooth should be on on the phone and you should be connected to WiFi so if you can turn both of those on on both devices (might be hard on watch unless it prompts you) but if you can get the same WiFi router as the last time it booted, it might reconnect automatically.
Once that’s done, you might end up down the “watch won’t restart” article which has a few more things to try before you contact Apple Support. Even though force restarting the watch isn’t ideal, you might try that as well one time once WiFi and Bluetooth are enabled to the max extent you can manage.

force restart - https://support.apple.com/en-us/HT204510
reset and restore - https://support.apple.com/en-us/HT204567