Sometimes torches doesn't change the state when block they're connected to recieves 1 tick pulse.

The most weird thing is that it's not constant.

I.e. only first on the right out of four fully identical falling edge detectors on the screenshot works.
And the working one doesn't cross chunk borders.

Workflow of the falling edge detector:

The output torch receives signal from the left repeater before the right torch turns off, so the output torch doesn't flicker.
When you remove the power, the left repeater stops powering block after 1 tick, and the Redstone torch turns on after 2 ticks, so there is a 1 tick interval when the block is unpowered and the torch should flicker.