Firebase v.11.1.0 CLI - OAUTH2 warning in command prompt - firebase

Question

I've updated firebase CLI today from version v.11.0.1 to v.11.1.0. Nothing else changed.
When I execute in cmd prompt any firebase commands (at least the one I use)
eg.
firebase deploy
I get this warning every couple of rows during firebase function deploy:
#firebase/database: FIREBASE WARNING: {"code":"app/invalid-credential",
"message":"Credential implementation provided to initializeApp() via the \"credential\" property failed to
fetch a valid Google OAuth2 access token with the following error: \"Error fetching access token: Error while
making request: getaddrinfo ENOTFOUND metadata.google.internal. Error code: ENOTFOUND\"."
}
After deploy ends successfully, in console every few seconds I get the same output of that warning. I also tried to execute firebase login --reauth authenticate once again. I did that successfully but the warning keeps popping up.
Does anyone knows what is the cause of this and how to get rid of it?
P.S.
After additional research, after few months later, I've updated firebase-admin and fire-base functions with new versions available and tried again all suggestions on the useful link here. But still, every single suggestion I tried there is not working form me:
re-authenticate
tried $env:GOOGLE_APPLICATION_CREDENTIALS (even that was found in official Google docs), for some apparent reason this is not working at all
changed and logged with different account (owner role)
and still same OAuth 2 error
NOTE: I have not tried file location since on firebase host, I do not want to put file because of security reasons and do not think this is a good practice.
Everything is linked to this line of code:
defDB = admin.initializeApp({
databaseURL: db_instanceUrl,
credential: admin.credential.applicationDefault()
}, 'targetDB');