Jar Jar event broken?

Is there an issue with the Jar Jar event?

I have finally made it to Tier 5 but, despite about 50 attempts so far, I cannot complete it. My primary issue is that none of the Jar Jar abilities seem to do as promised - I cannot apply death mark, the second special never stuns when they have protection/never applies expose when they don’t. 

I assume this is critical to gameplay because I simply cannot defeat any of the enemies in the final tier.