Shulker bullets will not trigger a tripwire hook.
Bug got reintroduced in 24w33a and is present ever since.
Steps to reproduce:
Build a cage for a shulker and let it shoot through a tripwire
Observe the tripwire not being triggered
Alternatively:
Setup a tripwire
Fly above it in creative and /summon shulker_bullet (which spawns a bullet that will fly down into it)
Observe the tripwire not being triggered
I am able to reproduce the reported behavior.