Delete goal plan from an individual

Normally we are able to delete an assigned goal plan from an individual and reassign as appropriate.

We have a situation with 4 of our employees who are unable to update their goals (they enter them and press save and nothing saves). This happens every now and then and when it does, we go into the goal plan, we delete against the individual and reassign to them and all is good.

For the 4 that we are currently having issues with, we are not able to select them. We can click in the tick box next to the Delete button but that doesn't allow the tick box next to the employee to become selectable.