Coins refusing to leave wallet

Please I’ve been trying to send dogecoin to a friend but it keeps pending then after a long while the doge coin is returned to my wallet. What could be the problem please??

Hi, @Lordjammy the transaction is pending due to low transaction fee, please update your app to the latest version as it has accurate doge transaction fee calculation. Please be informed that you cannot cancel nor speed up the transaction using the app. You have to wait for the Dogecoin miners to confirm your transaction. It may take a lot of time if your network fee is low. If it is still pending for a long time, the network will automatically drop and cancel your tx.

After How long do you figure the network will drop and cancel the transaction