Could not resolve encoder for end type?

I’ve got a collection of Event documents in my MongoDB database that contain various properties. One of which is an array of User IDs named “attendees”. I am trying to query the database for all the events who’s “attendees” array contains a certain user ID.

Here is one of my event documents:

_id: ObjectId(623ce74372a28f08dea6c959)
description: "Fun BBQ to celebrate my 21st!"
host: "623d03730e82c57fefa52fb2"
invitees: Array
location: "My address..."
name: "Fun Birthday BBQ"
private: true
date: "03/28/22"
end: "11:15 PM"
start: "06:35 PM"
attendees:Array
   0: "623d03730e82c57fefa52fb2"

Here is my query code in Android Studio using MongoDB/Realms

    String id = "623d03730e82c57fefa52fb2";
    Document queryFilter = new Document("attendees", id);
    app.getDatabase().events.find(queryFilter).iterator().getAsync(task -> {
        if (task.isSuccess()) {
            // Use list of events
        } else {
            Log.v("TEST", "ERROR: " + task.getError().getErrorMessage());
            // This error message is what i get! ^^
        }
    });

The task always seems to fail with the message:

TEST: ERROR: Could not resolve decoder for end type{"value": {"_id": {"$oid": "623ce74372a28f08dea6c959"}, "description": "Fun BBQ to celebrate my 21st!", "host": "623d03730e82c57fefa52fb2", "invitees": [], "location": "USC Village", "name": "Tom's Birthday BBQ", "private": true, "date": "03/28/22", "end": "11:15 PM", "start": "06:35 PM", "attendees": ["623d03730e82c57fefa52fb2"]}}

I have searched around and can’t seem to figure out what this error message means. Whats especially weird is that sometimes it works totally fine, and other times i get this message. It usually starts occurring when I’ve used my app for a little bit. Almost like a rate limit? So confusing!

EDIT: I have also tried using Document queryFilter = new Document("attendees", new Document("$in", Arrays.asList(user.getId()))); but this causes the same message sadly. I am able to query other attributes just fine!

Anybody have any idea what could be causing this? I am seriously at a loss here…