I've newly updated EmberZNet SDK 18.104.22.168 in Simplicity Studio. The new project I've trying to create, happens to be SDK 22.214.171.124.
This is how I created my Project: File->New->Project->Silicon Labs AppBuilder Projet->ZCL Application Framework V2->EmberZNet 126.96.36.199 GA Host 188.8.131.52->Z3Gateway next and Finish. On the top of Z3GatewayHost.isc file, it's written SiliconLabs Zigbee version:184.108.40.206.
I've used the same project creation method to create ncp-uart-sw Project, which worked fine with version 220.127.116.11.
I noticed the issue of different version when I am using cygwin to test the new SDK. When I execute Z3GatewayHost.exe, I get the following error:
ERROR: NCP EZSP protocol version of 0x08 does not match Host version 0x07
I guess this means I have used Z3GatewayHost old version, while my BRD4001A EFR32MG21 is with ncp-uart-sw SDK 18.104.22.168. I also found the same issue with other EmberZNet related demo projects.
This is a known issue of the new studio. The workaround for this issue is deselecting the EmberZnet 6.6.4 SDK through Simplicity Studio -> Window -> Preference -> Simplicity Studio -> SDKs then creating a new EmberZNet 6.7.0 project.