OK, I was having a similar problem, but just found part of the answer... I had "DC=lab, DC=lan" the space between the two parts was causing an issue, yet the test and sync were successful, and I could log in with a domain account after building that account for LDAP.
But still not showing any computers when I "search all", but when I go to groups and "Browse AD", I'm seeing all the containers. There are 5 member servers in the Computers OU, but I'll build some "client" computer accounts and see if it can see them.
Otherwise everything is going good when I actually read what the manual has written. Server 2022 running on XCP-ng in my lab while I figure out how to make things work before building this on production. Since I have part of this working now, I can at least move forward a bit and see where things go, I'll get some client computers on the lab that I can work with and see what I'm missing in the above.