Unable to make queries if not logged in

I have given Anonymous User the following permissions.
```
Execute arbitrary GraphQL requests
Execute persisted GraphQL requests
Use the GraphQL explorer
View media
View published content
```

When logged in, all queries seem to work fine. But when I log out, I can visit the `Explorer` page but the same queries return errors.

Below is the query.
```
query News {
nodeQuery(filter: {
conjunction: AND
conditions: [
{operator: EQUAL, field: "type", value: "News"},
{operator: EQUAL, field: "field_state.entity.name", value: ["NAT"]}]
}, limit: 5)
{
entities {
... on NodeNews {
nid
title
url: entityUrl {
path
}
body {
value
summary
}
discipline: fieldDiscipline {
entity {
entityLabel
}
}
fieldState {
entity {
entityLabel
}
}
}
}
}
}
```

Below is an error I get.
```
{
"errors": [
{
"message": "Internal server error",
"category": "internal",
"locations": [
{
"line": 2,
"column": 5
}
],
"path": [
"nodeQuery"
]
}
],
"data": {
"nodeQuery": null
}
}
```