Hoppers no longer set on fire with flint & steel. Many people use hoppers for wall sconces in builds, but currently you can't set the tops on fire while shift right clicking them. Fire tick is turned off for me.

I can set most anything else on fire still (i.e, stone, wood, leaves, etc.), it just seems to be hoppers that refuse to set on fire. I attached an image that shows a hopper that is old in my world that is still on fire, and one that is new that I just placed that won't light. So old hoppers that are already on fire are fine! Just can't light new ones  Thanks and keep up the awesome updates!