Ah I see..... New wheelset unfortunately so no idea. There's a gap between lock ring and first cog so it needs something. 1mm? Or 1.85? Or just see what works
Sounds like you do. I know I needed a spacer on my DT Swiss wheels that are designed to take 11 speed road. This is the one my wheels came with but pricey for what it is.
https://www.wiggle.com/p/dt-swiss-1...VQmHmCh3fHQeQEAQYASABEgIxRfD_BwE&gclsrc=aw.ds
If my google-fu is working, then 2.8mm is what you need. Start there and see how you get on. If you have a friendly lbs, ask if they have any butchered old style cassettes and try the spacers from there.
Shimano hollow tech bb spacers can also work but they are 2.5mm but may be enough.