realm::util::websocket::Error: - code: 10: Bad WebSocket response 4xx client errors

MongoDB Atlas App Services & Realm Atlas Device Sync
1

Upon building my app (while authenticated) on expo-client, getting an error at sync:

schema={MainRealmSchema}
	path='Main.realm'
	fallback={fallback}
	sync={{
		flexible: true,
		onError: (_session, error: any) => {
			console.log("ERROR: ", error)
		}
	}}

LOG ERROR: {“category”: “realm::util::websocket::Error”, “code”: 10, “isFatal”: true, “message”: “Bad WebSocket response 4xx client errors”, “name”: “Error”, “userInfo”: {}}

I don’t see any docs describing this error/code, what is code 10?

For additional context, I have a User schema with a property which has 3 nested arrays of objects

ex: user_draft_groups_categories_presets

My groups array has about 6 elements

My categories array has about 25 elements in each group array

My presets array has about 1-2 elements in each category array

Each preset array has an _id and a string.

The preset’s strings usually contain text of about 400 characters (sometimes more or less).

Interestingly, if I change all of the presets’ strings to a hardcoded “A”, restart/build the app, then it seems to work without error. However, if I change the data back to user input, then I get the error above.

Is this a particular limitation issue? Thanks.