Occasional TokenMismatchException

Occasionally, I'm seeing a TokenMismatchException in my laravel.log file from my site visitors. I might see only one or two of these per day out of thousands of visitors, so it's not a major issue, but it's still annoying me! In my Exception Handler file, I've added a log to see what route is causing the error to get a little more information, but I'm finding that it's not always the same route that causes the error.

I am using the Laravel Collective Form facade to create every one of my forms in my views, so I do not have any forms with missing tokens. Since the occurrence is so rare, I'm thinking that some people are just spending too much idle time on a page without clicking anything and causing the session to expire. To prevent against this, I added the LaravelCaffeineDripMiddleware to my global middleware in App\Http\Kernel. This may have helped a bit, but just now, I checked my logs and saw yet another TokenMismatchException. I looked at the stack trace and saw that the request definitely passed through the Laravel Caffeine middleware, so that's definitely working.

As a stop-gap, I have set up a way to gracefully handle these TokenMismatchExceptions by redirecting back to the previous page with back()->exceptInput('_token') so that the token is refreshed and letting the visitor know that they should submit the form again. However, I would prefer to simply solve whatever is causing this occasional error.

Does anyone have any ideas on how I could trace down what might be causing this?