Use different naming for fullbright, and always reset it back after setting it.

src/main/java/appeng/client/render/cablebus/P2PTunnelFrequencyBakedModel.java

@@ -49,7 +49,7 @@ public class P2PTunnelFrequencyBakedModel implements IDynamicBakedModel {
 
         cb.setTexture(this.texture);
         cb.useStandardUV();
-        cb.setRenderFullBright(active);
+        cb.setEmissiveMaterial(active);
 
         for (int i = 0; i < 4; ++i) {
             final int[] offs = QUAD_OFFSETS[i];
@@ -70,6 +70,10 @@ public class P2PTunnelFrequencyBakedModel implements IDynamicBakedModel {
             }
 
         }
+
+        // Reset back to default
+        cb.setEmissiveMaterial(false);
+
         return cb.getOutput();
     }