Find the answer to your question
When I revise the price of an item which is a part of a Promotional Sale, the sale no longer apply to that item. Is this expected?
Promotional Sales are governed by Markdown Manager rules. When item price or/and shipping price is/are revised through eBay Revising Item flow or ReviseItem API call, the item in question will be removed from a Promotional Sale.
ReviseItem requests will not fail, but will return the following warning: