Tango 10.1 client can not subscribe to events from Tango 7 server

Hi Tango experts!

We found that when a Tango 10.1 client subscribes to event from a Tango 7.2.6 server (IDL:Tango/Device_4:1.0) we get the following error: "Command ZmqEventSubscriptionChange not found"

Detailed error message...

>>> import tango
>>> d = tango.DeviceProxy("bl04/io/ibl0403-dev1-ctr0")
>>> d.subscribe_event("InputTerminal", tango.EventType.ATTR_CONF_EVENT, tango.utils.EventCallback())
Traceback (most recent call last):
  File "<python-input-3>", line 1, in <module>
    d.subscribe_event("InputTerminal", tango.EventType.ATTR_CONF_EVENT, tango.utils.EventCallback())
    ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/homelocal/sicilia/.conda/envs/tango_sub_test/lib/python3.14/site-packages/tango/green.py", line 231, in greener
    return executor.run(fn, args, kwargs, wait=wait, timeout=timeout)
           ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/homelocal/sicilia/.conda/envs/tango_sub_test/lib/python3.14/site-packages/tango/green.py", line 121, in run
    return fn(*args, **kwargs)
  File "/homelocal/sicilia/.conda/envs/tango_sub_test/lib/python3.14/site-packages/tango/device_proxy.py", line 1664, in __DeviceProxy__subscribe_event
    return __DeviceProxy__subscribe_event_attrib(self, *args, **kwargs)
  File "/homelocal/sicilia/.conda/envs/tango_sub_test/lib/python3.14/site-packages/tango/device_proxy.py", line 1898, in __DeviceProxy__subscribe_event_attrib
    event_id = self.__subscribe_event_attrib_with_sub_mode(
        attr_name, event_type, cb_or_queuesize, sub_mode, extract_as
    )
tango._tango.DevFailed: DevFailed[
    DevError[
        desc = Command ZmqEventSubscriptionChange not found
        origin = DeviceClass::command_handler
        reason = API_CommandNotFound
        severity = ERR
    ],
    DevError[
        desc = Failed to execute command_inout on device dserver/ni660x/bl04-01, command ZmqEventSubscriptionChange
        origin = virtual Tango::DeviceData Tango::Connection::command_inout(const std::string&, const Tango::DeviceData&) at (/home/conda/feedstock_root/build_artifacts/cpptango_1758199986038/work/src/client/devapi_base.cpp:2029)
        reason = API_CommandFailed
        severity = ERR
    ]
]

I quickly looked into RELEASE_NOTES.md and saw some refactorings of the zmq and notifd event machinery, but I do not interept them as we were removing support for this.

Note, I use conda-forge packages, both cpptango and pytango, version 10.1.1. When I downgrade to version 10.0.3 of both cpptango and pytango I can not reproduce this issue. I also use the 3.14 python, but I think it does not matter.

Sorry for this quick and maybe incomplete issue report, but I may be missing something, and for sure you will quickly point me to the right info.

Thanks a lot!