Anomaly detection not showing for some aws accounts in my central monitoring account.

I have a aws account designated for monitoring within my organization. I have shared five additional accounts to it and receive cloudwatch matrix successfully from all five.

I have created a dashboard to monitor cpu utilisation on a ec2 in each of the five accounts. I then set anomaly detection on each of the five matrix in the dashboard. Two of the matrix both in the eu-west-2 region show the anomaly range correctly. However the three other matrix, all in the us-west-1 region only show the matrix data and not the anomaly range.

What am I missing?