Where has suggested transactions gone when reconciling payments from card terminal to invoices?

The primary reason you're unable to find a match is that the bank transaction has a different amount and date than the checks entered in QuickBooks. 

QuickBooks suggests matches only for pending transactions with clear matches based on payment date, amount, and invoice details. Previously categorized or matched transactions won't appear as suggestions.

If you manually match a payment, it will no longer appear in the For Review tab.

To match them in your banking feeds, make sure the amounts and dates are the same.

Here's how:

1. Go to the Banking menu on the left-hand side.
2. Choose the relevant bank account.
3. In the For Review tab, locate the transaction you want to match with the check you created in QuickBooks.
4. Click on Find Match.
5. In the Match Transactions window, search for and select the check you created.
6. Once done, save.

To learn more about how to categorize and match transactions in QuickBooks Online, refer to this article: Categorize and match online bank transactions in QuickBooks Online.

Please keep in touch if you need additional assistance.