I picked up on the F.
The disconnect is not only in the negative space but the apparent “weight” of the F.
I’ve never been a fan of hard edged drop shadows used like that. In this case, with everything overlapping, it’s too busy.
Maybe try using the black as an extruded drop shadow instead, maybe even giving the red a black outline to give it more weight.
Note: by Extrude, I kinda sorta mean by hand. Illustrator’s extrude function can be a pile of crap if used straight up out of the box. To make a proper extruded letter, you have to copy the flat original, Do the extrusion using NO LIGHT so you get a solid shape, and even then use Expand and then use pathfinder to weld it flat. Then paste-in-place the original flat letters as a top layer. Don’t try to do it all in that awful algorithm.
If you are adding a black outline, do that to the flat letters first, then follow the rest of the steps.