Any gigiabit switch, from any vendor. There have been concerns in the past about using managed switches to connect satellites to Orbi routers over ethernet. I have not read similar concerns regarding this particular product, but there seems to be no advantage in paying more for a managed switch when an unmanaged switch will function just as well.
Netgear has set up a community forum specifically for the Orbi AX (WiFi 6) products. Most of the people who watch that forum are more likely to have experience with Orbi AX and know how to work it better than those of us who follow this "general Orbi" forum. Might be more likely to find someone who has a solution if the question is posted there: https://community.netgear.com/t5/Orbi-AX/bd-p/en-home-orbi-ax
