Repeaters don't stop sending power when unpowered. Instead, they start pulsing like a one tick clock would. This bug only happens when a repeater is powering redstone dust directly or through a block. Repeaters do behave properly when powering another repeater of redstone torch. The bug happens completely randomly it seems as it happened in some spots and not in others. Sometimes it happened acording to the length of the redstone.
It only happened when the repeater was facing north and was in a relation with a chunk boundary. also in a spot where it only happened with five redstone dust it later happened with just two. I have only tried replicating the bug in superflat worlds, but the bug happens often in all redstone contraptions.