Question on an issue transferring ETH from Coinbase to Coinbase Wallet

Disclaimer: I don't think this is an ETH issue, but a Coinbase issue. I have also posted this question on r/CoinBase to try and get answers. I am just hoping someone knows what this issue is and how to fix it.

I am new to this community, and I have done a lot of Googling and I can't find an actual solution to this problem: I have some ETH in my Coinbase Account, and would like to transfer it to my Coinbase Wallet. It won't allow me to transfer the amount I want, only like 3% of my total ETH supply. I would like to transfer it all if I could (or close to it) but it just isn't allowing me to do so?

As I was getting into crypto and researching best practices, everyone kept saying "use a wallet, it's more secure." so why won't Coinbase LET me be more secure? I'm not waiting on any transactions to finalize or anything like that. Can anyone help? I have seen a lot of posts with replies saying "I'm having the same problem" but I can't find a cause for this or a way to fix it.