Also provide some version numbers of VBR or agent, etc. Putting one sentence with no other context makes trying to give suggestions next to impossible.
This kind of error typically requires investigation of the logs. There are many reason we could fail to push certificate, but it does not make sense to guess everyone in my opinion.
Let Veeam Support check the logs, very likely this will be related to environmental factors.
@waqasali - Just wanted to follow up to see if you received an answer to your question. Please mark the best answer if this is resolved, including your own if needed.