cloudfoundry-client-reactor:5.6.0.RELEASE/5.7.0.RELESE have the error behind Proxy.

The same proxyconfiguration works fine with cloudfoundry-client-reactor:4.16.0.RELEASE

Caused by: io.netty.resolver.dns.DnsResolveContext$SearchDomainUnknownHostException: Failed to resolve 'api.sys.xxx' and search domain query for configured domains failed as well: [xxx]
at io.netty.resolver.dns.DnsResolveContext.finishResolve(DnsResolveContext.java:1047) ~[netty-resolver-dns-4.1.73.Final.jar:4.1.73.Final]