Probably since 1.14

When sending a redstone pulse through an unloaded chunk the current behaviour means that the first chunk the pulse is sent into will load for 1 gametick to save the redstone data. This causes 2 issues with redstone pulses:

1) the length of the pulse is lost: since the unloaded chunk is only loaded for 1 game tick the pulse length will be set to 1 game tick.

2) comparators and torches (might be others) will cause the signal to dissapear because they dont react to 1gt pulse. This is not just for comparators/torches on chunk borders but also those placed after for example a line of repeaters on minimum delay (since that repeater line will transfer a 1gt pulse length after passing through an unloaded chunk)

attached image: 5second pulse was sent through through unloaded chunk, after loading the unloaded chunks only repeater line caused the piston to fire, comparator loop doesnt activate at end of repeater line

Possible solution: loading the unloaded chunk for 2 game ticks might allow comparators and torches to react to the pulse and prevent the signal from being lost.