Logitech Harmony Hub - can't assign buttons

[clockworks]

I've got three hub-based Harmony remote setups, and I've just bought another Harmony Smart Control remote and hub to use in the spare bedroom.

I've set it up using the MyHarmony programme an my iMac, and it works fine apart from a couple of "missing" functions that I'd like to add to an activity. I've done this with no problem before on my other Harmony units, using the same programme on the same computer, so I'm familiar with how it works.

I can select the button that I want to assign, select the device, and select the list of available commands. When I get to the point where I have the option of choosing from "long press, short press or Both", it doesn't actually do anything. The button is still showing as "unassigned".
Weirdly, I can delete an already assigned function from a button, but I can't add it back in again.

I've tried changing the button assignments on one of my other hubs, and the same thing happens. I modified this other hub just 2 weeks ago, and everything worked as expected. Now it doesn't.

Any ideas?

[Lucid_AV]

Harmony announced they were pulling out of the remotes market. I guess at some point then that will mean their server-based set-up system will stop working. Is there a manufacturer-supported Harmony forum you can check for the latest status?

[clockworks]

I have just tried assigning the buttons using the Harmony Android app on my tablet, and it worked fine