1. /summon minecraft:marker ~ ~ ~ {data:{nbt:["\""]}}
(marker summoned)
2. /data get entity @e[type=minecraft:marker,limit=1]
(nbt is correct)
3. /tellraw @a {"nbt":"data.nbt","entity":"@e[type=minecraft:marker]","interpret":true}
(bug: empty line printed)
['"'], ["\"text\""], ["{\"text\":\"something\"}"] prints empty line too
Command mistake: an NBT list is not valid json, only strings are, if you make the whole list object quoted (eg with single quotes) it is accepted fine. any string that involves double quotes in the value is going to use single quotes on fetching data (
"\""->'"') which aren't valid as json objects.Invalid.