This bug was introduced in 24w45a.
Steps to reproduce (a video is attached):

1. Summon a shulker.
2. Build a tripwire directly above the shulker.
3. Notice the tripwire doesn't get triggered when the shulker opens.
4. Enter survival mode to aggravate the shulker.
5. Notice the tripwire doesn't even get triggered when the shulker opens fully.

Alternatively, this can also be reproduced with pressure plates:

1. Summon a down-facing shulker.
2. Build a pressure plate directly below the shulker.
3. Enter survival mode to aggravate the shulker.
4. Notice the pressure plate doesn't get triggered when the shulker opens fully.