Hi @adriennn thanks for your question!

Are you still facing this issue, and is it the same as reported in https://github.com/databricks-industry-solutions/routing/issues/2 marked as Open?

This might be related to the DBR Shared Mode architecture in DBR 15.4. I strongly suggest raising a support ticket for the same, so that we can effectively collect the details. Is it right to assume the same is doable in Single User Mode?