SEP v12.1 (unmanaged) doesn't grab new updates from LUA 2.3.2

We are using LUA v2.3.2 to pass updates to a computer with SEP v12.1.  The LUA has a download and distribute schedule that completed (assuming it got all updates for product SEP v12.1), but the SEP cannot find any new updates when it live updates to it.  The SEP client connects to LUA perffectly and downloads the 10 catalog files, but it shows 0 new updates when it is currently out of date (last definition is April).  What possible causes can I invesitigate to remedy this problem?