Many device are from particular group stop reporting to wsus console.
Step 1: Tried to re register with this command(wuauclt /detectnow resetauthorization /reportnow).
Step 2: Validate Issue reported device WindowsUpdate.logs found below major errors.
Step 3: By seeing above error. we have created different group and moved issue reported device to the new groups.
Step 4: Perform below step to re register.
Stop windows update services
Run regedit and go to KEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate
Delete the PingID, SUSClientID and the AccountDomainSID values
start the Wuauserv Service
From the command prompt run: wuauclt /resetauthorization /detectnow /reportnow
Step 5: After perform step 4, Verify device on wsus console device start reporting to the wsus.
Email: email@example.com, firstname.lastname@example.org
Follow us: https://www.linkedin.com/in/hiraniconfigmgr