What would cause FUTA to calculate wrong for one archive

Summary:

FUTA Glitch?

Content (please ensure you mask any confidential information):

Last week when I archived our forecast in NovFcst the FUTA tax was wrong. It was much higher than it was supposed to be. You can see in the screenshot that this had not happened before, all other archives worked as expected. FUTA is a member formula, the code is also below. There were no changes to this member formula. I checked the audit log, and there doesn't seem to be any changes to the FUTAMax either. What could cause this? could it be timing? It has everyone questioning the app.