Resource Price not updating in the activity when the resource is directly changed?

P6 EPPM 21.12.5

Here is the process that we are taking: Click on resources. Choose the resource whose cost needs to be updated. Click the 'Units and Prices' tab. Add a new price (or change the existing one). Go to activities. Click tools → recalculate assignment costs → recalculate. Click on an activity that is using the changed resource.

After following these steps, the resource is not updated with the new price within the activity. The price/unit and all costs are at $0.00 even though there is remaining units/time. However, if we add the same resource to the activity as a duplicate, that new resource will work fine, and update properly.