Turn on debugging in the Radius and MT and post the logs. Quick things to check is Radius secrets (though, if the secret was incorrect FR wouldn’t authenticate the router), and also the timeout values specified in the MT Radius configuration. Your timeout is more than likely to little.
AFAIK, you can start by just posting the MT Radius Statistics (/radius monitor 0 once)
I’ve adjusted the timeouts, this just seems to delay the time before it gets rejected.
I’ve laso checked secrets, this looks ok, I can see it in Freeradius giving it the OK and even handing the client and IP and other attributes.
The Mikrotik log and monitor say that it has timed out.