The local zone machine pool is not ready in rosa classic cluster with kms key arn

How reproducible:

100%

Env: stage

Step:
1. Create a byo vpc classic cluster with 4.19 version
2.Wait it ready and prepare a subnet in local zone
3.Create a machine pool in this subnet and check its status

Actual result :
The machine pool is not ready
Here is the job log

Expected result:
it should be ready

Additional information
The 4.18 version met this issue too