My old waffle iron suddenly sticks like glue—any way to rescue it without scrubbing off the seasoning?

I inherited this vintage waffle iron from my grandma and it’s been my breakfast hero for years. It’s got this lovely seasoned surface that made perfect waffles with a crispy exterior and tender inside. But recently, the batter started sticking terribly, turning my waffles into a mess instead of fluffy circles. I haven’t changed my recipe or cleaning routine - I still wipe it clean with a damp cloth and oil it lightly after each use. Tried heating it longer before pouring batter but no luck. I’m worried that aggressive scrubbing might ruin the patina Grandma worked on. Has anyone rescued an old cast iron or vintage waffle maker from this kind of sticky nightmare? Should I try re-seasoning it or is there some secret trick to bring back that non-stick magic without losing the character? Any tips on cleaning or seasoning would be fantastic!