Bitcoin transaction disappeared

I recently installed Bitcoin and am running a Bitcoin wallet. I also installed Sparrow, which created a cormorant wallet with Bit Coin Core.

1. I sent a transaction from Exchange to my Sparrow wallet – and it appeared in Sparrow
2. In Bitcoin Core, you will see it in your Cormorant wallet.
3. I would like to transfer the contents of my Cormorant wallet to my Bit Coin Core wallet and keep all my Bitcoins there.
4. Sent the contents of your Cormorant wallet to your BitCoin Core wallet
5. The transaction is processed on the blockchain and the Bitcoin core wallet address is verified
6. I can see the transaction amount being debited to my Uno wallet.
7. The transaction amount of my BitCoin Core wallet is not displayed.

Do you know what the problem is? Also, is it best practice to use a Bitcoin Core wallet to hold BTC before moving it to cold storage? I’m going to ignore Sparrow completely from now on as it didn’t work as expected with my Bitcoin Core wallet.

Thanks for the help and insight