Connection reset Traccar 5.9

Good morning everyone, I'm having the error in Traccar 5.9 and I can't figure out what it is due to
I get the following with different devices, they are all correctly registered and start reporting and then this happens

java.net.SocketException: Connection reset
        at java.base/sun.nio.ch.SocketChannelImpl.throwConnectionReset(SocketChannelImpl.java:394)
        at java.base/sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:426)
        at io.netty.buffer.PooledByteBuf.setBytes(PooledByteBuf.java:254)
        at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:1132)
        at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:357)
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:151)
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:788)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562)
        at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
        at java.base/java.lang.Thread.run(Thread.java:833)

It means that device closed the connection.

thanks Anton