Bob,

One out-of-the-blue question: Do you have both chains enabled on the radio? The factory default setting (for the RB912UAG-5HPnD at least) is to just enable chain 0.  Last time I checked, the configuration instructions on the HamWAN web site don't enable the second chain (chain 1).  Enabling the second chain can make a pretty substantial difference in net signal margin and stability.

Assuming that you are using a MIMO radio, to check this run:

/interface wireless monitor 0 once

You should have these lines in the display:

signal-strength:

signal-strength-ch0:

signal-strength-ch1:

tx-signal-strength:

tx-signal-strength-ch0:

tx-signal-strength-ch1: 

If you only have the following, then you are running in single-chain mode:

signal-strength:

signal-strength-ch0:

tx-signal-strength:

tx-signal-strength-ch0:

To enable both chains:

/interface wireless set 0 rx-chains=0,1 tx-chains=0,1

John KX7JM