I have recently noticed quite a few warnings like this in the server log. I have no idea if it is important but thought it was worth reporting.
[18-08-09 16:55:05.8380] Slim::Utils::Misc::msg (1252) Warning: [16:55:05.8367] DBIx::Class::ResultSet::single(): Query returned more than one row. SQL that returns multiple rows is DEPRECATED for ->find and ->single at /usr/share/perl5/Slim/Schema.pm line 2284
[18-08-09 16:55:05.8380] Slim::Utils::Misc::msg (1252) Warning: [16:55:05.8367] DBIx::Class::ResultSet::single(): Query returned more than one row. SQL that returns multiple rows is DEPRECATED for ->find and ->single at /usr/share/perl5/Slim/Schema.pm line 2284