Redstone Lamp did not activate piston

I tried a simple construction. I want to activate 2 pistons (one over another) with a redstone lamp. The lamp ist glowing but did not activate the 2nd piston. Its like the signal stops inside the lamp. See picture 1. If i draw a line of redstone from the first lamp it works. See picture 2. If i draw a line from the glowing 2nd lamp the redstone leaves inactive. The issue also occurs in other worlds. No ressource packs are active - only the default one.

 

This behavior also affects double pistons (extended pistons). Its like a general issue with restone signals.