One icon set breaks when I add a second

Hey All, I have been trying to add my own icons to my project via a icon font but I have 2 seperate sets that I want to add, the issue is now that when I successfully add one and I want to add the second one the first one breaks. I made sure that the icon Id’s are correct and also the font files are named differently just in case that could cause it.

Does someone know a solution to this ?

Thanks in advance.