Background

When a list of NBT values is displayed using the NBT component, the entries in the list are separated by commas, like so [<item 1>, <item 2>, <item 3>, ...].

The bug

When the items in the list are interpreted as text components using "interpret":true, the entries are no longer comma delimited: [<item 1><item 2><item 3>...].

Steps to Recreate

1. Create a container with 2+ items with custom names

   /summon chest_minecart ~ ~ ~ {Items:[{id:stone,Count:1b,tag:{display:{Name:"\"A\""}},Slot:0b},{id:stone,Count:1b,tag:{display:{Name:"\"B\""}},Slot:1b},{id:stone,Count:1b,tag:{display:{Name:"\"C\""}},Slot:2b}]}
   

2. Use the NBT text component to display the names of the items

   /tellraw @s {"nbt":"Items[].tag.display.Name","entity":"@e[type=chest_minecart]"}
   

   → The raw text components are comma delimited

3. Now use "interpret":true on the same items

   /tellraw @s {"nbt":"Items[].tag.display.Name","entity":"@e[type=chest_minecart]","interpret":true}
   

   → The interpreted components are not comma delimited

Disclaimer

Since interpret changes the nature of the text, I am unsure whether this is intended behavior.