Domain joined collector polling non-domain joined device

Just to be clear, on the veeam resource in LM, you’ve set wmi.user and wmi.pass to be the username and password of the veeam box, right? Since the target is not on the domain, if you don’t provide those, it will try to use the credentials of the account running the collector service on the collector. Since the collector is on the domain, those credentials won’t work. So, you have to provide the credentials of the veeam box on the veeam resource in LM so that the collector uses those instead of the collector’s identity itself.