all robo accounts(non-realtime users) are getting prompt "do you trust [domain].com". it started happening today suddenly.

Hello @Meher, Shankar (CORP),

As all the service accounts are getting the prompt "do you trust [domain].com" it looks like some change has happened on organization wide level.

Few things can be checked to narrow down the possible causes.

1. What environment these accounts are being used in.
2. What is the purpose of these accounts and where they are being used specifically.
3. Is there any specific application or service or action which is explicitly triggering this prompt.
4. Has there been any recent change or update in the systems? Any security update or patches, any certificate update or change. Any policy update or application update.

Looking at the prompt it seems there is certificate or trust issue, which can happen because of below reasons.

1. Certificate or Trust Store Change: If the domain [domain].com recently updated its SSL/TLS certificate any system that doesn't trust the new certificate authority (CA) might prompt this.

Robo/non-realtime users may not have the same trust store or profile as interactive users, so they might be seeing this for the first time.

2. Windows security update (or Edge/Chrome update) could have: Removed certain certificates from the trusted root store or changed how trust prompts are handled for non-interactive sessions.
3. A new GPO push or security configuration could be forcing prompts for unknown or new domains.

You may check the validity of the certificates by clicking the padlock symbol, it will show certificate validity details.

Check the trust store in MMC.

Check if there has been any recent update/patch to browser or windows.