Issue with PG user name (underscore issue)

Setup:
1) Using Digitial Ocean one click setup
2) Followed the steps to replace the HASURA_GRAPHQL_DATABASE_URL with my RDS postgres url which is on this pattern: postgres://@:5432
if somehow the username has an underscore in it. Example: post_gres the console throws an error:
"The character encoding of the plain text document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the file needs to be declared in the transfer protocol or file needs to use a byte order mark as an encoding signature."

the same DB works if the user name does not have underscore in it.