Lowdb (json database) with Next.js via Netlify returns internal server error 500 on API route, works locally

Question

I've got a really simple JSON flat file db setup that works when running locally but doesn't work once it's hosted on Netlify. I don't get any other error info besides a 500 error on the server. I get the error even if all I do is import the clusterDB object, so something is happening with the lowdb object. I've also tried using another json db library called StormDB and I get the same issue.

Return my API route with a static import of the json file (no db libraries) also works fine.

I'm new to Next.js and this seems related to maybe the SSR portion of things since the API routes run only on the server? Do I need to structure my files differently? Are these libraries not compatible? Lowdb says it works with Node, and everything works locally for me.

Here is my db init file (root/db/db.js)

import {Low, JSONFileSync} from 'lowdb'

// Cluster DB Setup
const adapter = new JSONFileSync('cluster-db.json')
const clusterDB = new Low(adapter)

// Initialize if empty
clusterDB.read()
clusterDB.data ||= { clusters: [] }
clusterDB.write()

export {clusterDB}

And my only API route (root/pages/api/clusters.js)

import {clusterDB} from '../../db/db'

export default async function handler(req, res) {

    await clusterDB.read()

    switch(req.method) {

        case 'POST':
            let newCluster = {severity: req.query.severity, comments: req.query.comments, date: req.query.date}
            clusterDB.data.clusters.push(newCluster)
            clusterDB.write()
            res.status(200).json({status: "Success", cluster: newCluster})
            break;

        case 'GET':
            if(clusterDB.data.clusters) {
                res.status(200).json(clusterDB.data.clusters)
            } else {
                res.status(404).json({status: "404"})
            }
            break;

    }

    res.status(200).json({test: "yay"})
}