Hello Fryelectricalser,
Welcome to the Community page,
It could be quite possible that the custom transaction number on the settings if turned off, which means QuickBooks will auto create its own number sequence. If it is turned off and you want to manually enter the start of your own sequence, you can turn it on and create a test invoice and see if that then resolves the number issue for you. Gear icon>Account and settings>sales tab>sales form content>custom transaction number> save>done
Any questions at all let us know, we'd be happy to help further in any way we can.