object caching causes corruption overnight

I am running an Avada themed site on windows azure. I have twice tried to optimize my website using minify and object cache and ended up with a site with no css, but only after waiting overnight. My testing process has been to enable object cache and minify css. Then thoroughly check that all is well by purging all caches and restarting the site. the second time I made some changes to the web config to rewrite the minify cache.

<rule name=”w3tc_rewrite_test” stopProcessing=”true”>
<match url=”^wp-content/cache/minify/000000/w3tc_rewrite_test” />
<action type=”Rewrite” url=”wp-content/plugins/w3-total-cache/pub/minify.php?w3tc_rewrite_test=1″ logRewrittenUrl=”true” />
</rule>
<rule name=”w3tc-minify-test-file” stopProcessing=”true”>
<match url=”wp-content/cache/minify/(.+/[X]+\.css)$” />
<action type=”Rewrite” url=”wp-content/plugins/w3-total-cache/pub/minify.php?test_file={R:1}” />
</rule>
<rule name=”w3tc-minify-file” stopProcessing=”true”>
<match url=”wp-content/cache/minify/(.+\.(css|js))$” />
<action type=”Rewrite” url=”wp-content/plugins/w3-total-cache/pub/minify.php?file={R:1}” />
</rule>
`
This morning I woke up and the site was unresponsive with a 500 error, but came back when I restarted it with incorrect styles. This is a very low traffic site.

Any thoughts on what would cause the cache to become corrupted overnight?

https://wordpress.org/plugins/w3-total-cache/