ISSUE RESOLVED but not necessarily how you would have expected.
A secondary DECISION TREE was failing based on a previous SHAREPOINT UPDATE record. The DECISION TREE was failing because it could not access a field from the RECORD associated with the SHAREPOINT UPDATE item. While this worked before, it was now failing for an unknown reason.
SOLUTION:
I removed all of the ITEM FIELDS associated with the SHAREPOINT UPDATE item throughout the flow. I had some help identifying the dependencies through the PEAK CODE option finding the reference to the title of the workflow item.
Once they were all set to the SHAREPOINT START item that kicked off the process, FLOW began to function correctly.