I have three instances of SQL 2017. One is the production server, the second is our soon to be replaced reporting server and the third is the new reporting server. Transactional replication runs fine on our current configuration. When I try to add a new subscription pointing to the new server, I'll randomly get an error telling me:
"The process could not connect to Subscriber 'NewServer'. (Source: MSSQL_REPL, Error number: MSSQL_REPL0)
Unable to complete login process due to delay in opening server connection (Source: MSSQLServer, Error number: 08001)"
I get this after having already set up new subscriptions that are up and running without issue.
Other than these two errors, nothing else is being logged.