/execute if entity fails to find @initiator

The bug

Inside of NPC dialogue, /execute if entity @initiator fails, when it should succeed. Other commands can use @initiator just fine.

How to reproduce

1. Download and open the attached world

2. Talk to the NPC thing
3. Click "IF" and "AS"

Expected results
Both buttons print a message

Observed results
Only the "AS" command prints a message

Notes
This is not the same as, but may be related to MCPE-164727. That one only occurs when experiments are on.