When the "Number of days adjustment for summarized payment date " is set to 0, the payments are neither summarized nor are they set with today's date (aka the date the vendor payment proposal automation ran + 0 days adjustment).

This means we can't use vendor payment proposal automation for proposals that are run today and need today as the payment/transaction date. We have to do manual proposals.

The summarized payment date adjustment works as expected when the value is not 0. We are able to use the automations for these scenarios.

This is a known issue logged in LCS. Microsoft is not planning to fix this.

Vendor Payment Proposal automation for summarized payments
Issue 546070 - Will not be fixed
KB number: 4602998

PROBLEM
Vendor Payment Proposal automation for summarized payments is not working when the proposal date is set to 0

REMARKS
Thank you for reporting this product issue. We agree that this is an issue for you and understand how this can be impacting your business. Unfortunately, the issue doesn’t meet the standards we require to be adjusted at this time.

Setting a summarize date time frame will achieve the desired results.