When you do /setblock and /fill, you cannot use "minecraft:repeater" even though you can use it when doing /give.
Example:
/give sfp70 minecraft:repeater = Given 1 [Repeater] to sfp70
/setblock ~ ~ ~ minecraft:repeater = There is no such block "minecraft:repeater"
/fill ~ ~ ~ ~ ~ ~ minecraft:repeater = There is no such block "minecraft:repeater"
Dupe of MC-47737. The block is unpowered_repeater.