doc: Added known issues related to Matter

Added two new known issues and fix to the smoke co alarm
readme.

Signed-off-by: Kamil Kasperczyk <[email protected]>

Author: kkasperczyk-no

doc/nrf/releases_and_maturity/known_issues.rst

@@ -504,6 +504,15 @@ Matter
 
 The issues in this section are related to the :ref:`ug_matter` protocol.
 
+.. rst-class:: v2-9-0 v2-8-0
+
+NCSDK-28567: Swap time after DFU takes a very long time
+  Due to the incorrect RRAM buffer configuration, the swap time after DFU can exceed three minutes.
+
+  **Affected platforms:** nRF54L15, nRF54L10
+
+  **Workaround:** Set the :kconfig:option:`CONFIG_NRF_RRAM_WRITE_BUFFER_SIZE` Kconfig option to ``1`` in the :file:`sysbuild/mcuboot/boards/nrf54l15dk_nrf54l15_cpuapp.conf` file of the application.
+
 .. rst-class:: v2-9-0
 
 KRKNWK-19846: Wrong command for the internal configuration build in the :ref:`matter_template_sample` sample documentation
@@ -2805,6 +2814,14 @@ Matter samples
 
 The issues in this section are related to :ref:`matter_samples`.
 
+.. rst-class:: v2-9-0
+
+KRKNWK-19861: ICD DSLS does not work with the :ref:`matter_smoke_co_alarm_sample` sample
+  According to the sample's documentation the ICD DSLS can be enabled by setting the :kconfig:option:`CONFIG_CHIP_ICD_DSLS_SUPPORT` Kconfig option to ``y``.
+  Additionally, the ICD Management cluster's feature map has to be set to ``0xf`` in the sample's ``.zap`` file.
+  This piece of information is missing from the documentation.
+  It will be added in the next version.
+
 .. rst-class:: v2-8-0
 
 KRKNWK-19691: Smoke CO Alarm sample does not have PM device enabled

samples/matter/smoke_co_alarm/README.rst

@@ -74,7 +74,8 @@ The device uses the SIT mode, when the wired power source is active.
 Otherwise, it switches to the LIT mode, to indicate that it is possible to save the energy, when using a battery power source.
 Dynamic switching is possible only if the ICD device meets all criteria for operating in the LIT mode (it has at least one client registered).
 DSLS support is disabled by default.
-To enable it, set the :kconfig:option:`CONFIG_CHIP_ICD_DSLS_SUPPORT` Kconfig option to ``y``.
+To enable it, set the :kconfig:option:`CONFIG_CHIP_ICD_DSLS_SUPPORT` Kconfig option to ``y`` and enable the feature support in the ICD Management cluster's feature map, by setting it to ``0xf`` in the sample's ``.zap`` file.
+Regenerate the source files after modifying the ``.zap`` file.
 
 In the LIT mode, the device responsiveness is much lower than in the SIT mode.
 However, you can request the device to become responsive to, for example, change its configuration.