After compiling sprites&dat with the transparency option, you need to "reload items" using the Items Editor (+ make sure that Items Editor using Transparency option too) and export the new items.otb file to the server.
ALSO,
you need to copy the Tibia.otfi
file (if you have edited this file via Sublime or another programming text editor, you should see "transparency: true") from the folder where you exported Tibia.spr and Tibia.dat to, and paste it into your Map Editor/data/your client version/.. here ..
Then, open RME, load the map, and save it.
After completing these steps with Tibia.otfi
- shouldn't have any glitches anymore.