When I make a new data asset and double click it to see details there are no details. I tried making a few different types of data assets and they’re all empty. If I make these assets in Unreal Engine 4.21 it works fine.
Below is an screenshot of what I see when I make an ARSessionConfig Data Asset in different engine versions. I right clicked in my content folder and choose Miscellaneous > Data Asset > ARSessionConfig then opened it.