@Anmol Singh, Thanks for posting in Q&A. Your understanding is correct. Based on the Delivery Optimization terms in the provided context, the "Group Bytes" in the Windows Update for Business report refers to the bytes delivered from Group peers. If a device is using Group DownloadMode, Delivery Optimization first looks for peers on the LAN and then in the Group. Therefore, if bytes are delivered from LAN peers, they are calculated in "LAN Bytes". In your picture, the devices are downloading the content from LAN peers instead of Group peers, which is why the Group Bytes under Content Distribution is showing 0 GB.
Hope the above information can help.
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