Hangs on reboot when updating firmware

I have 3 x PR4100. They are set to auto-update when they see new firmware.
Sometimes when rebooting (not only because of updating firmware) a PR4100 will hang with its blue light flashing and then I need to use the power button to shut it down and then start it up again.
So last night one of my PR4100s has auto updated to 193, one is still on 183, and one has disappeared from the internet. I know from experience that the disappeared PR4100 in in fact sitting there with its blue light flashing. Unfortunately it’s in a remote location to me, so that means I’ve lost the use of that device till I’m back in that location to manually restart it, which will not be for a while. I hope WD can understand how annoying that is. And I can see in this support forum that I’m not the only person with this issue.

See the dedicated subforum for the PR Series where people more familiar with that device may be able to assist. Generally this user to user subforum (My Cloud) discusses the single bay/single drive My Cloud devices.