When using the AC Tool with AEM Cloud Service [1] it seems that currently, the version during image build is always fixed to 3.0.10, which avoids using new features. This seems to happen due to a recent optimisation on AEM Cloud side.
[1] https://github.com/Netcentric/accesscontroltool/blob/develop/docs/ApplyConfig.md#installation-in-aem-as-a-cloud-service