I get the same result using an AIOC and a Baofeng HT with VARA-FM. Everything works great accessing a local packet BBS, so I know that the hardware is working, but when I try a Winlink session, I see that my radio connects, then I hear the Winlink node send a series of short bursts of data, but no decoding is taking place, and after a few iterations of this, the node disconnects, having neither sent nor received messages.
Dave KJ7WT