We enabled budget control for PO, but PO amount still can exceed total PR line amount

Summary:

We enabled budget control for PO, but PO amount still can exceed PR line amount

Content (please ensure you mask any confidential information):

We enabled budget control for PO

Total PR lines amount: 14 CNY

PR line 1: 1*10CNY=10 CNY

PR line 2: 1*4CNY=4 CNY

Processed this PR to PO, and increased the unit price of the PO.

PO amount: 17.5 CNY

PO line 1(PR line 1): 1*13CNY=13 CNY

PO line 2(PR line 2): 1*4.5CNY=4.5 CNY

Why was there no budget control on the PO to prevent the total amount of the PO from exceeding the total amount of the associated PR lines?

The amount of PO should not exceed the amount reserved by the associated PR.