Lately we have been observing that all the Contacts and Open oppty owners in our org. are changing to the Account owner if there is a change in owner on the Account. We do not have any automation for this. The idea (https://success.salesforce.com/ideaView?id=08730000000XrJFAA0) is still open, so I assume salesforce has not released this feature yet. Just wondering how this is happening and thought of checking with others in this forum?
I have raised a ticket with Salesforce where they are in the middle of analysis and partially confirmed that this is not salesforce native functionality.