WalletConnect v2 doesn't work with Mobile Safari on same device

Received this about WalletConnect v2:

> But does NOT work when accessing the dapp and wallet from the same device

Apparently it works if we scan a QR code, but not if we use mobile Safari on the same device. I'm not sure I reproduced the same problem, but I do get this:

1. Visit https://react-app.walletconnect.com with Mobile Safari
2. Connect
3. Connected
4. Tap personal_sign in dapp
5. Doesn't switch to AlphaWallet

Works with desktop browser, *but* if I do this:

1. Visit https://react-app.walletconnect.com with macOS Safari
2. Connect by scanning QR code
3. Connected
4. Go to homescreen on AlphaWallet
5. Tap personal_sign in dapp
6. Doesn't switch to AlphaWallet (can it show a local notification? We talked about this recently, if we can keep the app in the background for a while)
7. Tap to resume AlphaWallet

Expected
---
8. Prompt to sign

Observed
---
8. No prompt