So we have the same issue. We play with “release key to do action”, yet this feature only works with the opposite. you will need to use this macro:
/console ActionButtonUseKeyDown 1
This will change all of your abilities to feel very different to what you may have been used to for several years just to enable an accessability feature… Even when I enabled it I’m having some bugs with the feature where it just stops casting, so I have to keep repeating presses anyway.
Very poor implementation from my point of view.
So for now, it’s back to straining my arthritic fingers…