In Jira users can exist as an Atlassian account (Normal Jira user) and as a Jira Service Management customer while being linked to the same e-mail address. In this case, Jira can assign the Snipe-IT assets randomly to one of the users using the same e-mail address.

As a workaround, you can delete one of the users (either the Jira user or customer account) with the same e-mail address from your Jira instance. You might have to wait up to six hours for the asset to be re-assigned.