Currently, if a user is having Administer Projects permissions in multiple projects, and if the automation rule scope is restricted to these respective projects, the project administrator will not have an option to enable or to disable the automation rule.
As of now, the project administrator will be only allowed to enable or to disable the automation rule which is restricted to a single project where this user has Administer Projects permission.

Expectation:
If a user has Administer Projects permission let's say in Project A and Project B and if the automation rule is in scope for both these projects, then the project administrator should be able to enable or to disable the automation rule from the Project settings>> automation section.