Description

Prebid version 8.37.0 introduced new features allowing auction configurations to be independent of GPT. This version also introduced functionality to clear cached auction configurations by resetting them with null values using setConfig. However, in certain scenarios, cached auction configurations can persist, leading to duplicate impression calls, as observed in version 8.36.0. This ticket also provides additional context to issue #11102 which is pending discussions on the desired default autoconfig behaviour.

Issue Details

• In the latest version of Prebid, with fledgeForGpt.autoconfig set to true (default), cached auction configurations are reset correctly.
• However, when fledgeForGpt.autoconfig is set to false, additional API calls are required to trigger on-device auctions.
• Specifically, the publisher needs to call pbjs.setPAAPIConfigForGPT() whenever pbjs.requestBids is invoked and ensure it's called within the bidsBackHandler function.

Problem Scenario:

If the publisher neglects to call pbjs.setPAAPIConfigForGPT() for subsequent refresh calls, Prebid does not reset the previously set auction configuration, leading to potential duplicate impression calls.

Example Setup:

function initAdserver() {
    pbjs.initAdserverSet = true;
    googletag.cmd.push(function() {
        pbjs.que.push(function() {
            pbjs.setPAAPIConfigForGPT();
			...
        });
    });
}

function refreshBid() {
    pbjs.que.push(function() {
        pbjs.requestBids({
            timeout: 1000,
            bidsBackHandler: function() {
                // pbjs.setPAAPIConfigForGPT(); not called
                ...
            }
        });
    });
}

Steps to Reproduce:

• Set fledgeForGpt.autoconfig to false.
• Initiate bids with pbjs.requestBids and call pbjs.setPAAPIConfigForGPT() in the bidsBackHandler function
• For subsequent refresh calls, don't call pbjs.setPAAPIConfigForGPT()
• Observe behaviour

Potential Solution:

Previously set auction configs are reset by the logic within the slotConfigurator function, which executes when pbjs.setPAAPIConfigForGPT() is called. Automating pbjs.setPAAPIConfigForGPT() calls within setTargetingForGPTAsync() or similar functions could reduce the likelihood of configuration errors and mitigate potential duplicate impression calls.