SaveNexusIntegrated: saving in an existing HDF5 file fails

When saving data in an existing HDF5 file (different scan so different entry, should work normally) it fails:

[2023-02-08 18:03:41,149: ERROR/ForkPoolWorker-3] Task ewoksjob.apps.ewoks.execute_graph[ca9a8467-e4d3-4ece-95a5-b7b8bb3028a3] raised unexpected: RuntimeError("Task 'SaveNexusIntegrated' failed")
Traceback (most recent call last):
  File "/users/denolf/virtualenvs/blissoda/ubuntu_20_04/lib/python3.9/site-packages/ewokscore/task.py", line 337, in execute
    self.run()
  File "/home/denolf/dev/ewoksxrpd/src/ewoksxrpd/tasks/nexus.py", line 100, in run
    self.save_nxprocess(parent)
  File "/home/denolf/dev/ewoksxrpd/src/ewoksxrpd/tasks/nexus.py", line 133, in save_nxprocess
    nxprocess = parent.create_group("integrate")
  File "/users/denolf/virtualenvs/blissoda/ubuntu_20_04/lib/python3.9/site-packages/h5py/_hl/group.py", line 66, in create_group
    gid = h5g.create(self.id, name, lcpl=lcpl, gcpl=gcpl)
  File "h5py/_objects.pyx", line 54, in h5py._objects.with_phil.wrapper
  File "h5py/_objects.pyx", line 55, in h5py._objects.with_phil.wrapper
  File "h5py/h5g.pyx", line 166, in h5py.h5g.create
ValueError: Unable to create group (name already exists)

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/users/denolf/virtualenvs/blissoda/ubuntu_20_04/lib/python3.9/site-packages/celery/app/trace.py", line 451, in trace_task
    R = retval = fun(*args, **kwargs)
  File "/users/denolf/virtualenvs/blissoda/ubuntu_20_04/lib/python3.9/site-packages/celery/app/trace.py", line 734, in __protected_call__
    return self.run(*args, **kwargs)
  File "/home/denolf/dev/ewoksjob/src/ewoksjob/apps/ewoks.py", line 23, in wrapper
    return method(self, *args, **kwargs)
  File "/home/denolf/dev/ewoksjob/src/ewoksjob/apps/ewoks.py", line 35, in wrapper
    return method(self, *args, **kwargs)
  File "/home/denolf/dev/ewoksjob/src/ewoksjob/apps/ewoks.py", line 44, in execute_graph
    return submit(tasks.execute_graph, *args, **kwargs)
  File "/home/denolf/dev/ewoksjob/src/ewoksjob/worker/submit.py", line 9, in submit
    return func(*args, **kwargs)
  File "/home/denolf/dev/ewoksjob/src/ewoksjob/tasks/ewoks.py", line 30, in execute_graph
    result = ewoks.execute_graph(workflow, **kwargs)
  File "/users/denolf/virtualenvs/blissoda/ubuntu_20_04/lib/python3.9/site-packages/ewoks/bindings.py", line 28, in execute_graph
    return mod.execute_graph(graph, **execute_options)
  File "/users/denolf/virtualenvs/blissoda/ubuntu_20_04/lib/python3.9/site-packages/ewokscore/events/contexts.py", line 25, in wrapper
    return method(*args, execinfo=execinfo, **kw)
  File "/users/denolf/virtualenvs/blissoda/ubuntu_20_04/lib/python3.9/site-packages/ewokscore/bindings.py", line 56, in execute_graph
    return sequential.execute_graph(taskgraph.graph, **execute_options)
  File "/users/denolf/virtualenvs/blissoda/ubuntu_20_04/lib/python3.9/site-packages/ewokscore/graph/execute/sequential.py", line 122, in execute_graph
    task.execute(
  File "/users/denolf/virtualenvs/blissoda/ubuntu_20_04/lib/python3.9/site-packages/ewokscore/task.py", line 343, in execute
    raise RuntimeError(f"Task '{self.label}' failed") from e
RuntimeError: Task 'SaveNexusIntegrated' failed