What I expected to happen was...:

A type "left" chest check if it is alone and then play the sound

What actually happened was...:
Only type "single" chest and type "right" chest plays sound

(trapped_chest with type left too)

in the picture, only chest in diamond lines plays sound

Steps to Reproduce:

Place a left-double chest with a debug stick on a single chest / with the following command (removed before 1.16.1)

–

/setblock ~ ~ ~ minecraft:chest[type=left]