Screentime logging activity when all devices turned off and unplugged

Upgraded to Sequoia on Mac and macbook. Updated to IOS 18 on phones. Screentime has recorded 12-24 hours of activity whilst both computers are unplugged and completely shut down. Also showing pickups every hour the devices are turned off. Same is happening on phones. Phones are turned off every night. Note: only computers share the same Apple account. All devices have different Apple accounts. Is anyone else experiencing this after updating/upgrading? Ideas? Suggestions?