Hi, if I enable a workflow for purchase orders that replaces a prior one, what happens to all the Purchase Orders that are still in the approval process under the old workflow?

You'd have to check in SuiteAnswers to confirm, but I believe if you set a WF to Not Initiating, it will not fire for new transactions, but the workflow instances that are already in process will not be affected.

Yeah, I tested and just making the old one inactive seemed to continue functionality of the old flow. I will have to double check and make sure and if not change the WF to no initiating.

I think you need to set it to suspend, not initiating means that it won't run for any new records but will continue for any record already in the workflow