doubt

Good morning,My name is Danilo Araujo.I work in a technical support in Santo André, São Paulo.My company develope many systems for office envolving Accounting, Payment Roll, etc.We use Postgres 9.5 for ours applications.Our applications are used in our customers.In the end of every month, customers need to update their systems to liberate the access.Most of customers use the name of their server to connect the systems to their databases.I noticed that when they use the name of a server, occurs an error saying:An error occurred - template "database" does not exist.

I noticed that if I change the name of a server and I put the IP of the server, the error does not happens.Please, I would like to ask if this problem involve my systems or if is an error involving the Postgres.

Detail: I use to update the postgres always I can.
Thank you very much.Regards.Danilo Araujo.