Melee Weapon training

One of the more recent exmperimental builds:

I started with Pentjak Silat. At first I wielded a combat knife, everything was fine, I could use the combat style.
Then I swiched to wield a sledgehammer (which isn’t compatible with Silat), only to realize exactly that.

When I then switched back to my combat knife, however, it wouldn’t let me use Silat.
I tried switching weapons several times, with combat style turned on and off, but I couldn’t get Silat to work anymore.

Wait a turn.