A quick test with pingecho:

$ perl -MNet::Ping -MData::Dumper -e 'my $retval=pingecho("");print Du
+mper(\$retval);'
$VAR1 = \undef;
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shows that if you call pingecho() with an empty host, it returns undef, which should fail your if.
Are you sure that $dbSrvrUNC contains an empty string for the second ping?