imap-login: Error: BUG: Authentication server sent unknown id

[Tom Sommer]

I randomly get these errors on my Director

Aug 17 10:52:37 imap-login: Error: BUG: Authentication server sent 
unknown id 98448
Aug 17 10:52:37 imap-login: Warning: Auth connection closed with 2 
pending requests (max 2 secs, pid=27036, Received broken input: FAIL 
98448   user=user at example.com)
Aug 17 10:52:37 auth: Warning: auth client 27036 disconnected with 1 
pending requests: EOF

2.3.2.1

-- 
Tom