I thought protection didn't work either, but I had to enable it. The circle on the far right of your bottom UI panel needs to have a white aura circling it like opportunity attack does for it to be on. I had to move the Protection Ability above the Attack of Opportunity circle in that panel before I could turn it on. See if the same is true for your ability.
In the case of the riposte reaction missing, according to D&D5e rules you can only take one reaction although it would be nice if we could select beetwen them wich one to activate