No – it waits safely on your phone. If the signal drops while you press Save on someone's page, the words and dates you changed stay on that phone ("Saved on your phone – it'll go to the tree as soon as you're back online"), and "1 change waiting" shows at the top – press it to see what's waiting. The moment you're back online it sends itself. No need to type it all again. For example, say you're adding Grandad George's wedding date on the train and the signal goes in a tunnel – it simply waits until you're out the other side. Try to sign out with something waiting and you'll be asked first: Stay signed in, or Sign out anyway (it stays on that phone for next time). It's a small safety net for words and dates – pictures and family changes still need a signal.
Still stuck? Talk to a real person: send us a message, or email support@mywholefamilytree.com