When you say you tried resetting both, I assume you mean the problem MR and the MS that it is connected to? One thing you could try is physically swapping the problem MR with a working MR. If the problem MR continues to be the issue, then you might just need support to RMA it. If the other MR becomes the problem MR then it would point to an issue in the connection, maybe port config issue on the MS, bad cabling, etc. and further troubleshooting can be done to help narrow it down.