When Use Small Tool Bar Icons option is checked in Editor Preferences, the icons for Save, Add Slot, and Add Group in the Anim Slot Manager are not longer visible but register as still there and remain usabled
Below are screenshots of before Use Small Tool Bar Icons is enabled and after it is enabled
(Taken in 4.17.2 but looks the same throughout the other versions)
Expected: Icons do not completely disappear but register as still being there
Results: Icons are still usable but completely disappear
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-54822 in the post.