org.glassfish.jersey.servletServletContainer.service() hanging for too long

Question

I was analysing some slow API requests with Dynatrace. I saw this one that took 623 ms and it caught my attention. I was able to see the PurePath of the request and the first thing that happens is org.glassfish.jersey.servletServletContainer.service() spend 590 ms before calling the next method, as can be seen below:

The scenario of the test is like this:

Apache JMeter with 1 thread performing the same request everytime. On the first 100 seconds or so, the average response times is around 5 ms and then suddenly the response time increases and stay high until the end of the test. After the increase in response time, all the requests look like the on in the image. There is a huge hang time (apparently from Jersey).

I'm using the following Jersey/Jersey REST versions:

 <dependency>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-server</artifactId>
    <version>9.2.3.v20140905</version>
</dependency>
<dependency>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-servlet</artifactId>
    <version>9.2.3.v20140905</version>
</dependency>
<dependency>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-util</artifactId>
    <version>9.2.3.v20140905</version>
</dependency>

<dependency>
    <groupId>org.glassfish.jersey.core</groupId>
    <artifactId>jersey-server</artifactId>
    <version>2.22.2</version>
</dependency>
<dependency>
    <groupId>org.glassfish.jersey.containers</groupId>
    <artifactId>jersey-container-servlet-core</artifactId>
    <version>2.22.2</version>
</dependency>
<dependency>
    <groupId>org.glassfish.jersey.containers</groupId>
    <artifactId>jersey-container-jetty-http</artifactId>
    <version>2.22.2</version>
</dependency>

Is it a documented problem? Have anyone experienced that?

Edit 1: I was able to reproduce this with Postman. JMeter is sending Connection: close on the request header. JMeter's Connect time is low and the response time is higher than normal. It doesn't seem to be a problem of opening a new connection on every request.