[2021] Hey, encountered this bug. I have beaten their 3 of Palp, Thrawn, and R2 (And 7* Rolo) and am not eligible for any of the other challenges, yet they appear highlighted.

If you partially meet the requirements, the event will have a golden border and a holographic background. For the C-3PO event, for example, you need to be level 85 (this is a prerequisite requirement) and have 5 Ewoks. I hope this explains it (and makes sense). I agree that it looks overall inconsistent and have flagged it for review now.