I would check the trigger for the replenishment that is set for the product. There are 2 ways to trigger a reorder

1. Replenishment rules set on the product for a certain location. (min, max trigger) Inventory > Operations > Replenishments

2. Delivery Route - Similar to MTO, a route can trigger another operation. Do check the supply method set on the Delivery Order rule. If it is set to 'trigger another rule' it would skip checking stock. You might want to have it set as 'take from stock if unavailable trigger another rule' or 'Take from stock' if replenishment rules are set.

Post validating the trigger, you might want to look at reservations from product forecast page.'

The product is not MTO. Here's a screenshot.

https://tinyurl.com/ym3k74zn

Hi Bruce, 

Could you please share the configuration of the product?

Go to the product -> Select the product -> Click on the Inventory Tab -> Check the routes.

Based on your explanation, it's highly likely you have the Replenish on Order (MTO), Buy routes on the product and have a vendor assigned on the purchase tab of the product. 

When the client placed the SO for 9 units, the system triggered the MTO route and generated the RFQ to fulfil the SO. 

Example recreated on the runbot:

1. Created a product called "Product MTO"
2. Updated the stock. (No pending orders. but you can have a PO confirmed and not yet received as well)



3. Configured the routes (Operations)

4. Placed a SO for 20 units. As you can see the system generated a purchase order. 

5. This is the PO generated for the SO placed. As you can see, it was created for the 20 units. Without considering the stock on hand. 

I hope this clarifies your query. I would suggest you use reordering rules to trigger the RFQs when the product reaches the minimum quantity. 

Thanks.