Laravel 5.1 random timeout in ExcludeDirectoryFilterIterator

I'm seeing quite a few timeout errors on a big laravel 5.1 site:

[2018-05-23 17:02:35] production.ERROR: exception 'Symfony\Component\Debug\Exception\FatalErrorException' with message 'Maximum execution time of 30 seconds exceeded' in /var/www/vhosts/{site}/httpdocs/bootstrap/cache/compiled.php:16501 Stack trace: 0 {main}

Looking into the compiled.php file on that line number leads me to: ExcludeDirectoryFilterIterator@hasChildren

This function is from symfony/finder (version v2.7.47) https://github.com/symfony/finder/blob/34226a3aa279f1e356ad56181b91acfdc9a2525c/Iterator/ExcludeDirectoryFilterIterator.php#L73

I've used debug_backtrace on this function to see what's calling it and it looks to be laravel when loading the configuration from storage (local disk).

Does anybody know of any issue with this? Is the server disk getting hit hard at some times during the day causing loading the config to timeout?

Any help/suggestions much appreciated.

via Chebli Mohamed