A clustered index on GUID is not a good design. The very nature of GUID is that it’s random, while a clustered index physically orders the records by the key. The two things are completely at odds. For every insert SQL has to reorder the records on disk! Remove clustering from this index!
The time to use clustering is when you have a “natural” order to the data: time inserted, account number, etc. For time fields, clustering is almost free. For account number, it might be free or cheap (when account numbers are assigned sequentially).
While there may be technical ways around the GUID issue, the best idea is to understand when to use clustering.