IPS and Application signatures "Failed to Update"

Question

I have 3 XG105 that I manage. All are v17.1.3 (MR3). 
 Each of them are currently v9.15.36 and in the status, it says, Failed to Update. I have clicked on the Update Pattern button with no success. I have re-started the XG-105, clicked on Update Pattern button and then changed to downloading. However, changes back to 'Failed to Update' 
 Any thought show to resolve this?

LuCar Toni · Accepted Answer

In the Beta forum, it worked after couple of hours... 
 https://community.sophos.com/kb/en-us/123185 
 https://community.sophos.com/kb/en-us/132211 
 Check the u2d.

Paul Digby · Answer

36 hours later or so, 1 XG105 has now successfully updated to v9.15.37 
 
 Nothing done, just waited! But surely not right