submitter running into this issue:

Caused by: java.net.SocketTimeoutException: Read timed out
        at java.net.SocketInputStream.socketRead0(Native Method)
        at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
        at java.net.SocketInputStream.read(SocketInputStream.java:171)
        at java.net.SocketInputStream.read(SocketInputStream.java:141)
        at sun.security.ssl.SSLSocketInputRecord.read(SSLSocketInputRecord.java:475)
        at sun.security.ssl.SSLSocketInputRecord.readHeader(SSLSocketInputRecord.java:469)
        at sun.security.ssl.SSLSocketInputRecord.bytesInCompletePacket(SSLSocketInputRecord.java:69)
        at sun.security.ssl.SSLSocketImpl.readApplicationRecord(SSLSocketImpl.java:1271)
        at sun.security.ssl.SSLSocketImpl.access$300(SSLSocketImpl.java:76)
        at sun.security.ssl.SSLSocketImpl$AppInputStream.read(SSLSocketImpl.java:948)
        at java.io.BufferedInputStream.fill(BufferedInputStream.java:246)
        at java.io.BufferedInputStream.read1(BufferedInputStream.java:286)
        at java.io.BufferedInputStream.read(BufferedInputStream.java:345)
        at java.io.FilterInputStream.read(FilterInputStream.java:133)
        at sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(HttpURLConnection.java:3483)
        at shaded.oracle.org.glassfish.jersey.client.internal.HttpUrlConnector$2.read(HttpUrlConnector.java:210)

submitter has also suggested root cause of issue:
The problem here is that some previous request on that HttpClient set the ignoreContinue flag to false (because that's what made sense to the request), and then when the client was reused, the flag remains false -- but it should be set to true for a new request.

Possibility that JDK-8054022 would alleviate this issue.