Can't validate cachified with Zod schema? | Remix | Page 1

Hey, I'm trying to work my way through a tiny project whilst upskilling in FE & Remix. I'm probably doing something really dumb but I've been messing about for a while now on this to no avail - it's a Zod/Loader/Cachified issue for context.

My code works without a schema validation fine, but as soon as I introduce the schema validation either by checkValue within the cache or as a function which takes the response.json() as an argument and then validates the response - it tells me that the response.json() is all of a sudden undefined!?!

const dataLRU = new LRUCache<string, CacheEntry>({max: 30_000})
const dataCache = lruCacheAdapter(dataLRU)

export default function getById(id: string) {
    return cachified({
        // checkValue: zodSchema,
        cache: dataCache,
        key: id.toString(),
        async getFreshValue() {
            const response = await fetch(`url/${id}`)

            return await response.json()
        },
        ttl: 300_000
    })
}

This is a working example of my setup, a loader is calling getById and passing an ID and it's returning and caching the response as expected. As soon as I uncomment the checkValue: zodSchema line, i'm getting an error telling me that the input is undefined (I think).

{
"code": "invalid_type",
"expected": "string",
"received": "undefined",

#Can't validate cachified with Zod schema?