I still can't find out why. I've been testing the Greater Shield Bash and it is working correctly on my side...Are you sure there are no spells used on your defender? Does he have shield dualwield ? How many attacks does he do when using greater shield bash ?
I kidnapped your Thud and forced him to shield bash the past hour lol ... and I found the bug (+ the bonus int crafting bug) and I will patch the game in a couple of days with an asian new year mini event