Go to xbox networking in system settings (can just type into start bar search), and run the check... if you get "teredo is unable to qualify" then that has been linked by some to cause some issues with texture and data streaming.
If it is, to fix it properly raise an elevated command prompt (open as admin) and type:
netsh interface teredo set state type=enterpriseclient
hit enter, then type exit and enter.
Re-run the network test and it should pass.
Not got direct links off hand but it's been mentioned before in the Dev Q&A videos that xbox release is the DX12 release too. Btw it's not releasing on Xbox One, only Series X and S.
Also, not mentioned by name but you can read between the lines - the preview flighting opportunity (for SU5) in their june 3rd blog update said this:
“Would you like to participate in our next flighting opportunity? We have made significant updates and data changes to the sim and need a variety of PC setups to help test stability and performance. This build does not include any content changes but has significant performance updates we’d love for you to try out and provide feedback on.”