There could be multiple reasons that this happens:

  1.  Your internet was down or running very slow.
  2.  You were running an update on your back office, POS computer, causing the polling to timeout.
  3.  Your back office, POS computer was shut down over night.
  4.  You might have installed a program, creating a firewall, blacklisting R365.

Overall, if you are missing sales, you can contact R365 Support for assistance.