We started seeing this error on one of our merchants yesterday and now another one popped up today. We've solved this by sending an external_reference_id in our charge payload however this is what our request looked like prior to his issue popping up on the Clover E-Commerce API:
{ "source": "XXXXXXXXXXXXX", "tip_amount": 0 }
We've never sent an external_reference_id and wondering, is this now a required key? Or is this just another random error on the Clover API?