Not long ago there was an edge case with the failover transport where messages would end up being delivered out of order (see link)
Your case however, seems to be different. I'm not aware of bugs reported that match this description. If you attach the test case that you used to reproduce this problem we can use that to find the cause of the problem.
I wish these problems were that simple.
Every time I get an issue like this, I've never been able to reproduce it again. It is very frustrating.
Is it because I'm running on a Windows server that things are generally so unreliable.
I had a problem earlier today where three queues stopped being read from. I stopped and restarted the client with no change. But when I stopped and restarted the server they started flowing through again as if nothing had happened.
But can I repeat it, no. As I said, very frustrating.