Job scheduling with resource groups

We have a resource group (MG1) that included 6 different resources (M1, M2, M3, M4, M5, M6), all capable of performing the same work. All of them are set to infinite capacity.

Just recently, we have decommissioned 2 of the 6 presses and have removed them from the resource group. Now the resource group includes M3, M4, M5, and M6.

Our routes and production routes use the resource group (MG1) as the requirement type, so that when we run job scheduling, the scheduling engine selects one of the resources in the group.

Since we removed M1 and M2 from the group, we have not been able to schedule the production orders. We get an error message that there isn’t enough capacity. It almost seems as if it is still trying to schedule to either M1 or M2. If I add M1 and M2 back into the resource group, the production order can schedule without problem.

I tried putting an expiration date on the resources in the resource groups, hoping that scheduling would look at the next open date on a different resource, but that did not seem to help. I tried assigning a new calendar with zero working hours to the decommissioned resources, but that did not help either.

Does anyone have an idea on where I should start looking next or what else I can try?