In the primary I can see the secondary, but in the secondary I can't see the primary.
What does this mean?
Please run;
Dcdiag /v /c /d /e /s:%computername% >c:\dcdiag.log
repadmin /showrepl >C:\repl.txt
ipconfig /all > C:\dc1.txt
ipconfig /all > C:\dc2.txt
then put unzipped
text files up on OneDrive and share a link.