Weird grey/transparent block in exported image

[PixLab]

I did a try and discovered (I think) that there are at least 2 layers which are PNG with a color conservation in the transparency

If you want the background behind "VS"
In the layer group > New from visible > put it on top of the layer stack
Then File > Export
and in the export option > un-tick "Save color value from transprent pixels" (just to be sure)
(I only activate this setting to hide things in transparent pixels, see the end of the post **)
   

Result at 100%
   

** Put the one you exported with the transparent background in GIMP as a new image
Erasor tool Tick in the tool option at the bottom the "Anti Erase (Alt)" option
Then "Erase" the transparent part (have fun)