@initiator doesn't work in 1.19.50+ when experiments are enabled

Partner Rank: 2

Verification builds: 1.19.60
Regression builds: 1.19.40

Summary: The @initiator selector, used in dialogue, doesn't work anymore. We noticed this just today now that we have a working 1.19.60 build, but there is evidence this is also broken in 1.19.50.

Impact: This is completely blocking for some upcoming content. There is good news: it appears to not affect existing content on the store.

Repro Steps:

1. Download and open the attached world

2. /dialogue open @e[type=pig,c=1] @p test
   

3. Click the button

Expected Results: You get an apple and your name is printed in chat

Observed Results: No apple, no name in chat message

Screenshots/Videos attached: Yes