Observers don't detect "Some" block updates

I was experimenting with the new 1.16.20.50 Feature where walls, fences, glass panes, and iron bars will connect to open trapdoors. I used observers to detect changes. The things it detected with the connection: Walls. The ones it didn't detect: Fences, Glass Panes, and Iron Bars. Another one it can't detect is when a repeater gets locked even if the repeaters tecture changed and functionality