Just guessing here, but
[JVM-ARGUMENTS] [-Djava.net.preferIPv4Stack=true, -Xmn1024M, -Xms2048M, -Xmx4096M, -Xincgc]
4GiB (the "-Xmx4096M" part) may be cutting it close for the client if it has to load a lot of stuff, as is likely to happen when jumping. Especially if you allocate another 4GiB...