Custom CUrsor only shows up in certain Apps :(

Heya :D
\ So i finally figured out how to install Custom Cursors and decided to install this one :P
\ https://www.xfce-look.org/p/2347781

Sadly it only works with certain Applications like Firefox and such but for example uses the Stock Cursor on KeePassXC and STeam as well as some Video Games :(\

Does anyone by CHance have an Idea how to fix it? O.o
\ Or should i just try rebooting my Machine after applying the Cursor? >.>

Im on ARch Linux with Latest XFCE4 if that matters :P
\ Also Anyone got a Nyan Cat Cursor for Linux? >.>
\ Wouldve loved tp use this one but Cursors arent simple PNG Files you just apply to a Cursor it seems :(
\ https://www.cursors-4u.com/cursor/animated-nyan-cat-rainbow