We are a Navy group in Helmand River Valley with a HX50. Our GPS is 32 21 N and 64 42 E.
After struggling for 4 days to acquire satellite w6, we locked it today, commissioned the modem and were told by Bentley Walker we had optimal receive and transmit.  The internet was working smoothly at that time.  Then we abruptly lost the satellite.  We were able to relock, using Maxpeak, but only transiently and now cannot relock, despite repeating all of our previous steps.
Any help would be greatly appreciated.

Could the abrupt loss of lock (i.e. loss of receive LED light and signal quality drops from about 92, down into the range 0 - 29) be associated with winds moving the dish, winds moving the LNB cable, movement of the cables due to human activity (outdoors or next to the modem), temperature change of the LNB and cable ? Has a vehicle driven over the LNB cable ?

I would suspect a loose connection. The centre pin wire of the LNB cable connectors should stick out 1.5mm proud of the rim.  The braid must make good contact with the outer of the plug. There must be no fragments of braid wire short circuiting the cable.  When screwed in (using hand force only) the pin must go in smoothly and not push back the cable.

Power off at the AC mains wall socket before working on the LNB cable.  Leave the power supply module connected to the modem at all times

Once you get some definite satellite signal on the SATLOOK try waggling the LNB cables at the LNB and at the modem. There must be no change or intermittency.

When seaching for satellites note that they are in a sloping line. If you find any satellite, peak up and record the actual angles. Then move diagonally from there if you are on the wrong satellite. Up left or down right.

Best regards, Eric.