Expected behavior
Inverted Lamp should have normal model, and wires in Transmission creative tab should be ordered by type.

Versions
First beta 1.15.2

Screenshots/Videos

The unordered items may just be because you loaded a world that you used previously. Try a fresh world, should fix the order.

The lamp thing is a bug, still trying to figure it out

I just tried again with a new world and all items were sorted correctly. It's probably because I had created the world before Transmission was available.