Might check the system and replication event logs for clues, also check domain health via dcdiag, repamin tools. If further assistance is needed then please run;
Dcdiag /v /c /d /e /s:%computername% >C:\dcdiag.log
(run on PDC emulator)
repadmin /showrepl >C:\repl.txt
(run on any domain controller)
ipconfig /all > C:\dc1.txt
(run on domain controller 1)
ipconfig /all > C:\dc2.txt
(run on domain controller 2 if exists)
ipconfig /all > C:\dc3.txt
(run on domain controller 3 if exists)
set > C:\problemworkstationvars.txt
then put unzipped
text files up on OneDrive and share a link.