Hello Vince Asta
Welcome to Microsoft Q&A Platform, thanks for posting your query here.
Firstly, apologies for the delay in responding here and any inconvenience this issue may have caused.
Based on the information shared, in this specific case, "%60%3Cunset%3E%60
is an encoded string for <unset>
. It is used to indicate that the value for the session host name and user session ID is not set.
I would request you to share the documentation that you are following to assist you better on this.
If this workbook is created from Azure Monitor, then I would tag the case accordingly so that SME's from that service can add more insight and help on this.