i have the same issue, but there is a difference with my case. I have two elements, and the second element is a child of the first(it's because of menu hierarchy). Elements based on ol>li and div blocks. Second element drops down on hover. Both of elements have backdrop-filter and it works well for first, but when hover event fires and the second element drops down, it takes only background property, backdrop-filter doesn't work(i can see backdrop-filter property in the devtools and its not crossed out). I just stuck, i very appreciate for any advice with it.