Fighter Weapon Proficiency, How To Deactivate Totally?

[Reposter]

Hi guys, I made a Fighter as my first character. I gave him the Sword and Medium Shield Weapon Proficiencies. This gave him the Half Sword and Block abilities, the issue I have is once I click on one of the abilities during combat, I cannot turn either one off completely, it just gets stuck and I can alternate between Block and Half Sword but it just does not grant me the option to totally switch off the abilities to become both deactivated.

 

I can only switch off the abilities once I am out of combat though by clicking the ability twice it gets deselected for certain, I am not sure if this is a bug, anyone else having the same issues?