How to set CIS phy to 1M in LE Audio？

Hhhhh 2 days ago

In nrf5340 audio application( SDK2.9.0), I try to set phy to 1M in CIS( 1 gateway,2 headsets).

I made these changes：

Add in prj.conf:

CONFIG_BT_CTLR_PHY_2M=n
CONFIG_BT_AUTO_PHY_UPDATE=n
CONFIG_BT_PHY_UPDATE=n

In C:\ncs\v2.9.0\zephyr\include\zephyr\bluetooth\audio\audio.h , set to 1M:

In C:\ncs\new_CIS\src\bluetooth\bt_stream\unicast\unicast_server.c ,set to 1M:

After changing these, the CIS still use 2M.

I want to know how to make the CIS PHY 1M.

Thank you for your help.