Ensure the Fix Pack is at the very top of your Active Resources list. Other texture packs might be overriding the UI files.
If you have installed the pack but still see UI glitches, consider the following: file name hovertextfixpackmcpe121mcpack link
Navigate to and move the Hover Text Fix to the top of your active list. Why is my Hover Text still broken? Ensure the Fix Pack is at the very
on the screen after you’ve stopped hovering over an item. file name hovertextfixpackmcpe121mcpack link