When matching and reconciling the invoice you receive from LMB with the deposit in your bank account this would usually clear the invoice on your dashboard.
Some points to consider first;
Have you entered any information manually in Xero in terms of invoices?
Have you checked Awaiting Approval for anything outstanding?
Have you checked your bank for multiple deposits for the same amount?
If you've checked those things, this article will help troubleshoot as to why the invoice is still showing;
The easiest way to check for duplicate invoices within Xero is by doing a search on the value to see if there is more than one invoice;
Business > Invoices
Reports > Search for Journals in the search bar
From here you can search for the value.
If you are still unsure after these checks, please get in touch with the support team and we'll be able to assist further.