Action definition contains lower case letter cannot be removed in function

Hello expert,

When I define the action of a function, I entried a lower case letter in action: it should be "MDS_PPO2", but I entried "MDS_PPo2".

After I saved this function, it has two dupliacted tcode like below:

Then I try to remove the one with lower case letter:

After save the function, the removed one is back again:

I also tried to disactivate the action and remove again, but it didn't work.

Does anyone know how to remove this action with lower case letter?

Thanks and regards,

Lynn Gao