Relay UploadManagerData not sending

I have a v9.5.13 relay on Win2012 and for the past week, it hasn’t been processing any files in D:\Program Files (x86)\BigFix Enterprise\BES Relay\UploadManagerData\BufferDir\sha1

I’ve restarted the BES Relay service, restarted the server, renames \Temp to \Temp.old, but still nothing.
I enabled debug logging on the Relay and nothing in the log about uploadmanager. The relay’s filldb data seems to be processing fine.

I have other relays that are successfully sending uploads to the same root server.

Any suggestions?