It seems like there could be many reasons why Hold Invoice is being defaulted to true by the system. None of the SO lines are marked Time/Materials, which is one reason I saw on here. Any other known causes for the system to put a Hold on an Invoice?
do you use avalara? if so it could be that and unable to calculate tax on the invoices.
You should be able to turn off tax connect enabled in company maintenance or company configuration for your test environment.