When linked pipe is copyed/blueprinted, and Quantum Fabricator built the pipe, the pipe losses its filter tag.
This is because qf uses script raised revive, and this mod calls LinkedPipe.on_entity_created_nonplayer_cause. This function doesn't pass the event.tags to the built entity function, unlikely the robot built and player built ones. (Idk if there is a design choice for this or if something else uses this function.)

Solution: add the event.tags back to the on_entity_created_nonplayer_cause funciton.

in scripts/linked_pipes.lua, in function LinkedPipe.on_entity_created_nonplayer_cause(event), line 132:
if event.tags then LinkedPipe.built_entity(event.entity, nil, event.tags) else LinkedPipe.built_entity(event.entity, nil) end