Using custom notification script via user notification

CMK version:2.4.0 p14
OS version: SLES SP6

The custom notification scripts works as global notification rule.
If its a user notification, following error occurs in the notify.log
I’m sure, that this way works before the major notification update.
User notifications still use the old configuration UI

Is there a workaround or patch available?
Thanks in advance

Error message:

2026-01-28 16:21:49,929 [20] [cmk.base.notify] - adding notification of a-bost05 via pushsafer.py
2026-01-28 16:21:49,929 [40] [cmk.base.notify] ERROR:
Traceback (most recent call last):
File “/omd/sites/xx/lib/python3/cmk/base/notify.py”, line 493, in locally_deliver_raw_context
return notify_rulebased(
^^^^^^^^^^^^^^^^^
File “/omd/sites/xx/lib/python3/cmk/base/notify.py”, line 779, in notify_rulebased
notifications, rule_info = _create_notifications(
^^^^^^^^^^^^^^^^^^^^^^
File “/omd/sites/xx/lib/python3/cmk/base/notify.py”, line 896, in _create_notifications
final_parameters: NotifyPluginParamsDict = _rbn_finalize_plugin_parameters(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File “/omd/sites/xx/lib/python3/cmk/base/notify.py”, line 1061, in _rbn_finalize_plugin_parameters
parameters.update(rule_parameters)
ValueError: dictionary update sequence element #0 has length 1; 2 is required