Laravel Model with fillable not updating

I have an Eloquent Model called Coin, with fillable attributes set. I have a Form on the page, which when I check $request->all() I can confirm is submitting correctly.

I have a FormRequest object with rules returning an empty array. (I'll add them later.)

The problem is, FormRequest $request->validate() returns an empty array which is probably wrong. It should be returning an array of my request items. I cannot figure out why this is happening!

Here is my controller method:

public function update(UpdateCoin $request, Coin $coin)
    {
        $this->authorize('update', $coin);

        $coin->update($request->validated());

        $this->log('Coin %s (%s) was updated by user %s.', $coin->name, $coin->symbol, auth()->user()->id);

        $request->session()->flash('success', 'alerts.coin_updated');

        return redirect()->route('admin.coins.show', [$coin->id]);
    }

This is the FormRequest class:

class UpdateCoin extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            //
        ];
    }
}

This is the Coin Model:

/**
 * Defines a coin model.
 */
class Coin extends Model
{
    use Eloquence;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name',
        'symbol',
        'pair',
        'logo',
        'description',
        'primary_color',
        'secondary_color',
        'website',
        'wallet_name',
        'wallet_site',
        'wallet_description',
        'exchange',
        'marketcap',
        'active',
    ];
...

var_dump($request->all()) proves the form is submitting with the new values.

var_dump($request->validated() returns an empty array, which shows that something is wrong, but I have absolutely no idea why.

I have another model which does the same thing, and I've spent a few hours now comparing them and they're for all intent and purpose, identical.

via Chebli Mohamed