If orders and payments aren't working, more than likely it's associated with the NCR Aloha Transaction Gateway Helper service being stopped. This is critical to ensuring PeopleVine and Aloha can communicate in the cloud. Follow these steps to resolve:
Login to the Back of the House (BoH) machine
Go to the start button and then click on run or press the Windows Key and R
Type in services.msc and hit enter
Find the NCR Aloha Transaction Gateway Helper service and right click it to start it. This will automatically start the NCR Aloha Transaction Gateway service as well.
Once started, your orders and payments will start syncing. Please note if this was down overnight, you will lose any modifier data and will need to re-assign the customer to the order (this is an NCR glitch in 12.3).