Quoting Coinbase Wallet

These measures will help you in coming out of the connection issue that you are facing with the Coinbase extension. If not, then you can even connect with the customer support team of the wallet. The concerned team will assist you on the right path.
https://sites.google.com/coinswalletes.com/coinbasewallet/home
https://sites.google.com/coinswalletes.com/mew-wallet/home