Vmware, Ubuntu, KDE Plasma, starting new windows processes hangs for 30 seconds

Edit: Appearantly, it is a KDE/Plasma problem. Installing and using Gnome gets rid of it. But I do prefer KDE, and woul like to get it back.

Many scenaria, basically most that opens a new window with help from KDE plasma. Note that "new window" from Konsole or Chrome or others, does not exhibit this. I.e. the window appears "instantly" in that case.

this is perhaps the simplest example:

• From the command line, do "konsole".
• The whole system gets unresponsive. I have a digital clock running, and the seconds stop counting.
• About 30 seconds later, the new Konsole appears, the seconds continue counting and the system unfreezes.

I tried "strace -t -o /tmp/strace konsole", and this is what I see at the relevant moment:

...08:21:00 munmap(0x7c8108167000, 147456) = 008:21:00 poll([{fd=3, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=3, revents=POLLOUT}])08:21:00 writev(3, [{iov_base="\226\1\3\0j\3\0\0\0\0\0\0", iov_len=12}], 1) = 1208:21:00 futex(0x7ffc7dbe9448, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 0, NULL,                     FUTEX_BITSET_MATCH_ANY) = 008:21:32 futex(0x563396bd8218, FUTEX_WAKE_PRIVATE, 1) = 008:21:32 fcntl(8, F_GETFD)              = 008:21:32 fcntl(8, F_SETFD, FD_CLOEXEC)  = 008:21:32 poll([{fd=3, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=3, revents=POLLOUT}])...

So, 32 seconds of wait for some futex condition. I tried some googeling but it doesn't see to lead anywhere, so can anyone help me getting forward?Sometimes the problem goes almost away (2-5 seconds wait) after running the booted system a day or two, and sometimes rebooting helps (for a while). So it is kind of random.

Details:Host: Windows 10 Enterprise, 22H2Vmware: VMware® Workstation 17 Player, 7.5.2 build-23775571Guest: Ubuntu 24.04 LTS / NobleOperating System: Kubuntu 24.04KDE Plasma Version: 5.27.11KDE Frameworks Version: 5.115.0Qt Version: 5.15.13Kernel Version: 6.8.0-31-generic (64-bit)Graphics Platform: X11Processors: 12 × 12th Gen Intel® Core™ i9-12900HMemory: 20,6 GiB of RAMGraphics Processor: SVGA3D; build: RELEASE; LLVM;Manufacturer: VMware, Inc.Product Name: VMware Virtual PlatformSystem Version: None

I was expecting the new konsole to show up a bit faster.