New generated jhipster app not showing front-end in prod mode (404 error)

I generated a completely new jhipster app without touching the generated source. After that I build with the commands (according to docs):

./gradlew -Pprod bootWar jibExportDockerContext && docker build -t
myimage build/jib-docker-context

a docker image and started in docker. But I cannot reach the angular frontend.
It gives me a 404 error with the following console output

A parser-blocking, crosssite (i.e. different eTLD+1) script,
https://linkhelp.clients.google.com/tbproxy/lh/wm?sourceid=wm&url=http%3A%2F%2Flocalhost%3A8080%2F&hl=de&site=localhost%3A8080&error=http404&js=true,
is invoked via document.write. The network request for this script MAY
be blocked by the browser in this or a future page load due to poor
network connectivity. If blocked in this page load, it will be
confirmed in a subsequent console message. See
https://www.chromestatus.com/feature/5718547946799104 for more
details.
Qc @ fixurl.js:142
ke @ fixurl.js:143
(anonymous) @ fixurl.js:143

During the building and starting the image (container) there are no erros. The backend (management/health) is reachable through curl. Starting the app in dev mode is working (but not in docker container). The only thing what I think is a little bit confusing is that the Hazelcast ist in dev mode when starting in prod mode.

jhipster-app_1 | 2019-03-01 09:04:30.981 INFO 1 — [
main] com.hazelcast.system : [172.21.0.3]:5701
[dev] [3.9.4] Hazelcast 3.9.4 (20180420 – b8001d5) starting at
[172.21.0.3]:5701
jhipster-app_1 | 2019-03-01 09:04:30.982 INFO 1 — [ main] com.hazelcast.system : [172.21.0.3]:5701
[dev] [3.9.4] Copyright (c) 2008-2018, Hazelcast, Inc. All Rights
Reserved.
jhipster-app_1 | 2019-03-01 09:04:30.983 INFO 1 — [ main] com.hazelcast.system : [172.21.0.3]:5701
[dev] [3.9.4] Configured Hazelcast Serialization version: 1
jhipster-app_1 | 2019-03-01 09:04:31.283 INFO 1 — [ main] c.h.s.i.o.impl.BackpressureRegulator : [172.21.0.3]:5701
[dev] [3.9.4] Backpressure is disabled
jhipster-app_1 | 2019-03-01 09:04:31.840 INFO 1 — [ main] com.hazelcast.instance.Node : [172.21.0.3]:5701
[dev] [3.9.4] Creating MulticastJoiner
jhipster-app_1 | 2019-03-01 09:04:32.027 INFO 1 — [ main] c.h.s.i.o.impl.OperationExecutorImpl : [172.21.0.3]:5701
[dev] [3.9.4] Starting 2 partitioenter code heren threads and 3
generic threads (1 dedicated for priority tasks)
jhipster-app_1 | 2019-03-01 09:04:32.042 INFO 1 — [ main] c.h.internal.diagnostics.Diagnostics : [172.21.0.3]:5701
[dev] [3.9.4] Diagnostics disabled. To enable add
-Dhazelcast.diagnostics.enabled=true to the JVM arguments.
jhipster-app_1 | 2019-03-01 09:04:32.052 INFO 1 — [ main] com.hazelcast.core.LifecycleService : [172.21.0.3]:5701
[dev] [3.9.4] [172.21.0.3]:5701 is STARTING
jhipster-app_1 | 2019-03-01 09:04:34.329 INFO 1 — [ main] com.hazelcast.system : [172.21.0.3]:5701
[dev] [3.9.4] Cluster version set to 3.9
jhipster-app_1 | 2019-03-01 09:04:34.330 INFO 1 — [ main] c.h.internal.cluster.ClusterService : [172.21.0.3]:5701
[dev] [3.9.4]

JHipster v5.8.1 H2 (dev) postgres (prod)

Source: StackOverflow