I want to hide these new Youtube annotations that appear at end of movie. UBO selector proposes ##.ytp-ce-element-show.ytp-ce-size-640.ytp-ce-bottom-right-quad.ytp-ce-video.ytp-ce-element, looks to specific to me, so I cut it to ##.ytp-ce-element-show. Works fine, but this filter did not appear in logger. Probably because is added dynamically when element is shown.

Where it appears:

https://youtu.be/s5RM81_6vC8?t=265 (annotation is show at 4:27)

Filter used

youtube.com##.ytp-ce-element-show

Not shown in logger

Another filter is working fine

youtube.com##.ytp-ce-element

Firefox 53, UBO 1.10.7rc4