Two android farms - one single account Farms can't be moved

One friend of mine and her hubby have 2 different farms on two different devices but only one account on Google+.
So far no problem until she bought a new tablet and wanted to move her farm.
No way. When the pop up drops up, it doesn't allow her to load it but only a brand new one!
it seems there's nothing in the cloud, neither her farm nor her hubby's farm..
checking the connection to G+ in both their farms, the button is "greyed", so it seems they aren't connected to G+ and probably they're not saving their games. Is it possible? Is there a way to move the farm from the old device to the new one?
Thanks for helping! She's so worried.. :(:(:(

No helpers? No suggestions? Ask if you need more specifications, maybe I wasn't clear enough :(

Did you read the troubleshooting thread at the top of the page? There may be some help there although I know that Supercell do not recommend having two farms on one device. Another suggestion is that your friend contacts support in game.

Thanks Connemara for your reply.
They don't have two farms on one device, but two different farms on two different devices, but one single G+ account.
Both farms are linked to that account and I suppose this might be the problem.
Troubleshooting thread doesn't help in this case. I hoped someone else in the forum have experienced the same problem and solved it.
Pity...