I can share a few insights about customer deposits in QBO. When you receive a payment for a sale, you should deposit it physically to your bank.
Tagging the payment as deposited in QuickBooks doesn't mean the amount goes through your bank immediately. If you haven't visited the F.I., you may put the funds in the Undeposited Funds account in QBO.
To record a sale paid by check, use a Sales Receipt. Here's how:
Click the + New icon and select Sales Receipt.
Complete the sales detail and enter UndepositedFunds as the Deposit to account.
Hit Save and Close.
Create a bank deposit once this check is endorsed to your financial institution. Here's how:
Still on the + New icon, select Bank Deposit this time.
Pick the account you used to deposit the funds from the Account drop-down.
Locate and mark the payment (sales receipt) from the Select the payments included in this deposit section.
Click on Save and close when done.
If you linked your account for online banking, the deposit will be downloaded once cleared. From there, you can match the bank entry to the deposit.