device.ua always empty in the first prebid bid request

[GhadaSalah]

Describe the bug

Hi team,
we've tested the new iOS version 2.1.6, the prebid-mobile version is correct, and the device.ua field no longer includes the app version. However, we still experience an issue, in the first prebid bid request, the user agent is always empty. It seems as though, Prebid sdk is not able to detect the user agent in the first request.

To Reproduce

Here is the request:
{ "app": { "bundle": "484115113", "domain": "leboncoin.fr", "ext": { "prebid": { "source": "prebid-mobile", "version": "2.1.6" } }, "name": "Leboncoin", "publisher": { "id": "3296" }, "storeurl": "https://apps.apple.com/fr/app/leboncoin/id484115113", "ver": "6.89.0" }, "device": { "connectiontype": 2, "ext": { "atts": 3, "prebid": { "interstitial": { "minheightperc": 1, "minwidthperc": 1 } } }, "h": 844, "ifa": "3F6929E8-CF38-4F99-A17A-72A2902740C7", "language": "fr", "lmt": 0, "make": "Apple", "model": "iPhone", "os": "iOS", "osv": "17.0.3", "pxratio": 3, "ua": "", "w": 390 }, "ext": { "prebid": { "cache": { "bids": {}, "vastxml": {} }, "storedrequest": { "id": "3296" }, "targeting": {} } }, "id": "368AAD93-FB1F-4A75-B137-48926F5F2EBE", "imp": [{ "banner": { "format": [{ "h": 844, "w": 390 }], "pos": 7 }, "clickbrowser": 1, "ext": { "prebid": { "storedrequest": { "id": "30312907" } } }, "id": "A1252508-3C58-4829-A142-5CB17840E609", "instl": 1, "secure": 1 }], "regs": { "ext": { "gdpr": 1 } }, "source": { "tid": "3280A47A-8EE8-4D22-BA07-13746839F0B7" }, "user": { "ext": { "consent": "CPyc0sAPyc0sAAHABAFRDXCsAPLAAHLAAAAAJoNB_G_dTyPi-f59YvtwYQ1P4VQnoyACjgaNAwwJiVLBMI0EhmAIKAHqAAACIBAkICZAAQBlCAHAAAAA4IEAASMMAAAAIRAIIgCAAEAAAmJICABZC5AAAQAQgkwAABUAgAICABsgSDAAAAAAFAAAAAgAAAAAAAAAAAAAQAAAAAAAAgAAAAAAAAAAEAAEABAAAAAAAAAAAAAAAAAEEAQATDQuIAGwJGQmkDCIAACMIAgCgBABRAJCwQAEBKgAEEYACjAAAABFAAAAAAAAEBAAAAAAgAQgAAAAYEAgAAAEAAAAEAgEAAAAACAAABAAAAAEAMAAAAAAgAIAAAIAQAAhAAgAJAgACAAAAgAAAAAAAAAgEAAAAAAAAAAAAAAAAQAxQAGAAIgoDAAMAARBQIAAYAAiCgA" } } }

Expected behavior

For all bid requests to correctly include the device.ua field.

Thank you
Ghada.