I'm not sure what you're asking but the login error is happening only on the default instance. The server has 2 additional instances and i'm not seeing this error on those.
This is a new server that i setup using virtual accounts for all instances and today changed them all to active directory accounts, but still seeing that domain\computername$ login failure on the default (MSSQLSERVER), just happened a few minutes ago, in fact its happening exactly every 5 minutes.
I shut down the browser service and the full text service just to check and its still happening exactly every 5 minutes.
The only other services are the VSS Writer and SQL Telemetry (CEIP service)
Also i'm using the dbaTools powershell module (Get-DbaService) to switch the service accounts.