purchase requisition workflow - requisition stuck in initiation phase

We have a workflow established for purchase requisitions where the employee central submits a requisition - if it is over $500 it must be approved by the next level role called Practice Manager, otherwise it goes to AP for approval. If an employee with the Practice Manager role submits a purchase requisition greater than $1,250, it moves to a director for approval. This was working until recently, now the workflow works when the $500 or $1250 limits are reached, and the requisition requires a second approver, but if the requisitions fall below the limits, the requisitions are stalling at the initiation phase.