Redstone dust not visually updating

when i build this particular clock, the redstone dosent glow when on, and the F3 information dosent register any power, yet the redstone lamps light up.

i have posted a video to show what was happening
https://www.youtube.com/watch?v=dJUWnTuNyhs&feature=youtu.be

the clock has 2 slime blocks in the center, that you cannot see in the video but the rest you can see.

as the video shows the lamps update as expected but not the redstone.