diff --git a/src/main/kotlin/io/emeraldpay/dshackle/quorum/QuorumRpcReader.kt b/src/main/kotlin/io/emeraldpay/dshackle/quorum/QuorumRpcReader.kt
index fbe72bf4..4a8911b9 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/quorum/QuorumRpcReader.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/quorum/QuorumRpcReader.kt
@@ -161,7 +161,7 @@ class QuorumRpcReader(
                     is JsonRpcException -> err
                     else -> JsonRpcException(
                         JsonRpcResponse.NumberId(key.id),
-                        JsonRpcError(-32603, "Unhandled internal error: ${err.javaClass}")
+                        JsonRpcError(-32603, "Unhandled internal error: ${err.javaClass}: ${err.message}")
                     )
                 }
                 quorum.record(cleanErr, null, api)
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/GrpcHead.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/GrpcHead.kt
index d8434fbe..2b9ece14 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/GrpcHead.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/GrpcHead.kt
@@ -80,6 +80,7 @@ class GrpcHead(
             .setTypeValue(chain.id)
             .build()
         return client.subscribeHead(chainRef)
+            .doOnError { log.error("subscribeHead err: ${it.message}", it) }
             // simple retry on failure, if eventually failed then it supposed to resubscribe later from outer method
             .retryWhen(Retry.backoff(4, Duration.ofSeconds(1)))
             .onErrorContinue { err, _ ->
diff --git a/src/main/resources/log4j2.xml b/src/main/resources/log4j2.xml
index ffabce8b..08e5d92d 100644
--- a/src/main/resources/log4j2.xml
+++ b/src/main/resources/log4j2.xml
@@ -26,6 +26,10 @@
 
         <!-- Reactor Netty produces warnings that are ok,
              ex. when Dshackle closes a connection too fast and Reactor Netty HTTPClient doesn't like that -->
+        <Logger name="io.grpc.netty" level="error" additivity="false">
+            <AppenderRef ref="STDOUT"/>
+            <AppenderRef ref="STDERR" level="warn"/>
+        </Logger>
         <Logger name="reactor.netty.http.client" level="error" additivity="false">
             <AppenderRef ref="STDOUT"/>
             <AppenderRef ref="STDERR" level="warn"/>