Enable snapshot_copy on an existing aws_redshift_cluster resource

I’m trying to add snapshot_copy configuration to an existing aws_redshift_cluster resource to enable cross-region snapshot copy for DR purposes. When I run my deploy, the job sits on “cluster modifying…” for 30+ minutes with no completion before timing out. Is this something that still has to be applied with a null_resource, or is there something stopping it from applying to an existing cluster? I know I can go into AWS Console and apply the change manually without any issues, so I’m trying to determine where the issue is with TFE.