You need to use the invoice # you want and click save and new. You may have to do it several times until QB remembers.
Resolution for 'click save issue: 'Invoice Sequence Not Working in Quickbooks 2016 Desktop' available: Yes.
The click save issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the click save issue yourself by looking for a resolution described in the article. If it is a complex click save issue or you are unable to solve the issue, you may contact us by clicking here or by using other click save support options.
For more information about resolving issues related to click save in Quickbooks/QBO or to get support for the issue 'Invoice Sequence Not Working in Quickbooks 2016 Desktop', click the link below: