The WalletConnect v1 protocol has some scaling issues, and the v2 protocol version isn't quite ready yet. Sorry about that.
So here's how to fix the problem when the WalletConnect session has been dropped/closed by your wallet, but Graflr didn't get the memo.
To disconnect a bad session, or just disconnect the app from the wallet.
Navigate to Profile > Settings > Wallet
Tap on your wallet address
When prompted select DISCONNECT to close out the connection.
You can now start a new connection with the same steps:
Navigate to Profile > Settings > Wallet
Tap on your wallet address
When prompted select CONNECT to initiate the connection process.
That should get Graflr back on speaking terms with your wallet. Happy Minting!