Because of the wallet you are using, you might not get sufficient answers, because i don't expect too many experienced users to be using this wallet for their Bitcoins; anyway you have gotten some good exlanations on the possible cause of your problem. But just a little advise, don't use Coinbase wallet for your Bitcoins, it is a closed source wallet and what happened with Atomic wallet is still fresh in everybody's minds, so there is prolly no better time to move over to an open source wallet like Electrum, and if you have any inquiry about it, i'm pretty sure you'd be inundated with suggested solutions because it is one of the Bitcoin wallets that is widely recommended.