Problem linking extension from asterisk with Rainbow Cloud

Hi,
I have a problem with the setup of my test environment. Everything on CTI Media Bridge has status Connected but I can't see any extensions on Rainbow user to get linked with it.

My environment:
192.168.64.126 - Asterisk FreePBX
192.168.64.131 - Rainbow WebRTC
192.168.64.143 - Rainbow CTI & Media Bridge on WIndows 10

In WebRTC mpcheck I see one test failed:

PBX_DOMAIN SIP OPTIONS ...
siptest ... /opt/mediapillar/cv/mpstc -S -a192.168.64.143 -d5060 -w2
ERROR: 111 openTCP, failed to connect
Checking protocol sip, fqdn (none), addr 192.168.64.143, dst port 5060, src port 20695
[FAILED] 20211007-074837 failed
registration access ...
traceroute -n -m -4 -T -p 5060 192.168.64.131
max hops cannot be more than 255
[OK] route 192.168.64.131

And in Media CTI Bridge logs I see:

2021-10-05 20:14:27,417 - [WaitForExtensionsList] Start - Getting(Wait) Extensions List For Connector:ASTERISKAMI
2021-10-05 20:14:57,558 - [WaitForExtensionsList] End - Getting(Wait - Null Case) Extensions List For Connector:ASTERISKAMI Extensions List:0
2021-10-05 20:14:57,558 - [ProcessConfigChannelRequestBO] Object reference not set to an instance of an object.
System.NullReferenceException: Object reference not set to an instance of an object.
at RainbowCCCAgentBIS.ConfigChannelProcessing.ProcessConfigChannelRequestBO(ConfigChannelRequestBO objConfigChannelRequestBO)