I'm seeing the exact same thing (as in https://forums.intel.com/s/question/0D50P00004dgLM3/windows-10-hyperv-and-intel-wireless-ac-9560-160...) on a Lenovo T490s (20NX) running Windows 10 Enterprise 1909 latest patches and the latest drivers from Lenovo 184.108.40.206 (the problem is also there in 220.127.116.11) and latest drivers from Intel. It's unlikely a Windows problem since most of the similar problems are caused by drivers. It works fine with a ThinkPad USB 3.0 Ethernet Adapter and fine on a older Lenovo using AC 8265. Since this is a company laptop I'm have filed a support request with Microsoft Premier support and they are currently investigating this problem.
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We have also sent your feedback to the proper department for review. It is worth noting that we cannot guarantee that your request is going to be addressed.
Since Microsoft* is currently investigating this issue, we will close this case. In this scenario, if this performance issue is being caused by Intel® Wireless Adapters, their support team can contact Intel directly in order to work on this issue.
Intel Customer Support Technician