HTTP disconnection when upgrading from version 2 to version 3

I’m currently trying to migrate from nexus2 to nexus3. Most of my repos have worked, but with one I’m currently struggeling.

Its a simple hosted repo with some npm packets in it.

The scan works just fine, but after that it always breaks with http disconnection read timed out.

Here you can see the logfile during the upgrade:
2019-11-21 19:45:33,547+0100 DEBUG [qtp1270283552-227] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:34,551+0100 DEBUG [qtp1270283552-227] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:35,556+0100 DEBUG [qtp1270283552-225] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:36,564+0100 DEBUG [qtp1270283552-227] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:37,578+0100 DEBUG [qtp1270283552-227] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:38,579+0100 DEBUG [qtp1270283552-227] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:39,585+0100 DEBUG [qtp1270283552-227] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:40,590+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:41,599+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:42,603+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:43,608+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:44,118+0100 INFO [plan-executor-4-thread-2] admin org.apache.http.impl.execchain.RetryExec - I/O exception (java.net.SocketTimeoutException) caught when processing request to {}->http://localhost:9081: Read timed out
2019-11-21 19:45:44,119+0100 INFO [plan-executor-4-thread-2] admin org.apache.http.impl.execchain.RetryExec - Retrying request to {}->http://localhost:9081
2019-11-21 19:45:44,614+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:45,616+0100 DEBUG [qtp1270283552-227] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:46,621+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:47,633+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:48,636+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:49,633+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:50,640+0100 DEBUG [qtp1270283552-227] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:51,646+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:52,657+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:53,665+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:54,662+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:55,668+0100 DEBUG [qtp1270283552-227] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:57,395+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:45:58,563+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:46:00,484+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:46:01,494+0100 DEBUG [qtp1270283552-227] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:46:02,516+0100 DEBUG [qtp1270283552-308] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:46:03,521+0100 DEBUG [qtp1270283552-257] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:46:04,141+0100 WARN [plan-executor-4-thread-2] admin com.sonatype.nexus.migration.client.http.MonitoredHttpRetryHandler - Considering HTTP retry after 9 failures, most recent: Read timed out
2019-11-21 19:46:04,142+0100 INFO [plan-executor-4-thread-2] admin com.sonatype.nexus.migration.client.http.MigrationRequestMonitorImpl - Request failed during failure mode: Read timed out
2019-11-21 19:46:04,142+0100 INFO [plan-executor-4-thread-2] admin com.sonatype.nexus.migration.client.http.MigrationRequestMonitorImpl - Delaying until Thu Nov 21 19:48:54 CET 2019
2019-11-21 19:46:05,556+0100 DEBUG [qtp1270283552-257] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:46:07,489+0100 DEBUG [qtp1270283552-236] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:46:08,498+0100 DEBUG [qtp1270283552-257] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC
2019-11-21 19:46:09,506+0100 DEBUG [qtp1270283552-236] admin com.sonatype.nexus.migration.ui.ProgressComponent - read SYNC

How can I get that repo upgade to work? Both machines run on the same server.

Thanks!