Why cheque is still showing as add on banking page for review when I have already manually matched it?

Hi Flex1, thanks for joining the Community.

It's unusual that a duplicate transaction would be downloaded from the bank connection - we'd recommend first to check your online bank statement to ensure that charge wasn't cleared twice. 

If the duplicate is genuine, and you've already matched the correct transaction to your manual transaction in QB, you can remove this from the for-review feed by ticking the check-box to the left > scroll to the top of the page and select exclude. 

If you don't already, we'd also recommend regularly clearing the cache on your browser to ensure QuickBooks is running as smooth as possible - you can see how to do this here. 🙂