JiC it helps anyone else, I was in the same boat but I used the Developer Link above to request a Call back and a helpful member of the Apple Developer Support team was able to diagnose a reference to UIWebView from some unused third party (AFNetworking) code. Not sure why I wasn't getting an email notification to highlight that this was the source of my woes but am able to see the Builds appearing now.
Topic:
App Store Distribution & Marketing
SubTopic:
App Store Connect
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