Galaxy watch active 2 was working very good with s21 ultra untill a recent update. Ever since that the watch built too many problems such as freezing and boot failure as well as outdated time. After resetting the watch now it keeps disconnecting from the phone.rest all problems are solved
Please bring the device to a Samsung Service Center to have it checked out by a technician and resolve the issue.
Find the nearest service center online or on Samsung.com