Reported here https://github.com/bitcoin/bitcoin/pull/12629#issuecomment-381095603 by @Empact.  I've seen it now in a few different travis jobs, including:

https://travis-ci.org/bitcoin/bitcoin/jobs/366157920
https://travis-ci.org/bitcoin/bitcoin/jobs/366139851

From my initial investigation it seems like there may be an actual bug in block announcement, so I'm  opening this issue to track.
{
    AssertLockHeld(cs_main);
    assert(lp);
    
    
    if (lp->maxInputBlock) {
        
        
        if (!chainActive.Contains(lp->maxInputBlock)) {
            return false;
        }
    }
    
    return true;
}
bool CheckSequenceLocks(const CTransaction &tx, int flags, LockPoints* lp, bool useExistingLockPoints)