When I install addonpacks with more locos, the icons from all Locos are away.
And I have this problem since the older version of IR.

PC:
Ryzen 7 2700
16GB RAM
RX Vega 56

Yes

are you running it with 3D icons aactive?

if you go into your settings config for IR, you have the option to shut off 3D icons. if you turn it off it will show the icons without bugging out

What version of IR? latest version has no icon option, renders it all differently.